ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • AERODYNAMICS  (846)
  • 1990-1994
  • 1980-1984
  • 1975-1979  (798)
  • 1955-1959  (48)
  • 1935-1939
  • 1925-1929
  • 1977  (383)
  • 1975  (415)
  • 1958  (29)
  • 1957  (19)
  • 1929
Collection
Years
  • 1990-1994
  • 1980-1984
  • 1975-1979  (798)
  • 1955-1959  (48)
  • 1935-1939
  • +
Year
  • 1
    Publication Date: 2004-10-07
    Keywords: AERODYNAMICS
    Type: NASA Lewis Research Center Inlet Workshop; p 427-480
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2004-12-03
    Keywords: AERODYNAMICS
    Type: Supercritical Wing Technol.: A Report on Flight Evaluation; p 111-120
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2006-01-16
    Description: The physical principles of flight, and the consideration of atmospheric composition and aerodynamic forces in the design and construction of various types of aircraft are discussed. Flight characteristics are described for helicopters, rotary-wing aircraft, short and vertical takeoff aircraft, and tailess or variable geometry wing aircraft. Flow characteristics at various speeds are also discussed.
    Keywords: AERODYNAMICS
    Type: Soviet Aircraft and Rockets (NASA-TT-F-770); p 24-80
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2006-01-11
    Description: The application of computer techniques for solving Navier-Stokes equations in support of wind tunnel tests is discussed. The ILLIAC IV computer is considered for this purpose and its limitations are analyzed. The author states that improved computers will make it possible to solve many aerodynamic problems and reduce the amount of wind tunnel testing required for adequate data processing.
    Keywords: AERODYNAMICS
    Type: NASA/Univ. Conf. on Aeron.; p 211-212
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2006-01-11
    Description: Research within NASA relating to the nature of lift-induced vortex wakes behind large aircraft and the means whereby the hazard they represent to smaller aircraft can be alleviated is reviewed. The research, carried out in ground based facilities and in flight shows that more rapid dispersion of the wake can be effected by several means and that the modification of span-loading by appropriate flap deflection holds promise of early practical application.
    Keywords: AERODYNAMICS
    Type: NASA/Univ. Conf. on Aeron.; p 143-168
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2011-10-14
    Description: A thoroughly documented experiment is reported that was specifically designed to test and guide computations of the interaction of an impinging shock wave with a turbulent boundary layer. Detailed mean flow field and surface data are presented for two shock strengths which resulted in attached and separated flows, respectively. Numerical computations are used to illustrate the dependence of the computations on the particulars of the turbulence models. Models appropriate for zero pressure gradient flows predicted the overall features of the flow fields, but were deficient in predicting many of the details of the interaction regions. Improvements to the turbulence model parameters were sought through a combination of detailed data analysis and computer simulations which tested the sensitivity of the solutions to model parameter changes. Computer simulations using these improvements are presented and discussed.
    Keywords: AERODYNAMICS
    Type: AGARD Flow Separation; 13 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2011-10-14
    Description: A method is developed for solving the laminar and turbulent compressible boundary layer equations for separating and reattaching flows. Results of this method are compared with experimental data for two laminar and three turbulent layer, shock wave interactions. Several Navier-Stokes solutions are obtained for each of the laminar boundary layer, shock wave interactions considered. Comparison of these solutions indicates a first order sensitivity in C sub f to the computational mesh selected in both the viscous and inviscid portions of the flow. Comparison of the present boundary layer solutions with the Navier-Stokes solutions and with data for a given Mach number indicates that as long as the separation bubble is small, the boundary layer approximation yields solutions whose accuracy is comparable to the Navier-Stokes solutions.
    Keywords: AERODYNAMICS
    Type: AGARD Flow Separation; 12 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2011-08-16
    Description: The formulation of mathematical models of aeronautical systems for simulation or other purposes, involves the transformation of aerodynamic stability derivatives. It is shown that these derivatives transform like the components of a second order tensor having one index of covariance and one index of contravariance. Moreover, due to the equivalence of covariant and contravariant transformations in orthogonal Cartesian systems of coordinates, the transformations can be treated as doubly covariant or doubly contravariant, if this simplifies the formulation. It is shown that the tensor properties of these derivatives can be used to facilitate their transformation by symbolic mathematical computation, and the use of digital computers equipped with formula manipulation compilers. When the tensor transformations are mechanised in the manner described, man-hours are saved and the errors to which human operators are prone can be avoided.
    Keywords: AERODYNAMICS
    Type: Aeronautical Quarterly; 26; May 1975
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2011-08-16
    Description: A closed-form solution for the sound radiation from multipole sources imbedded in an infinite cylindrical jet with an arbitrary velocity profile is obtained. It is valid in the limit where the wavelength is large compared with the jet radius. Simple formulae for the acoustic pressure field due to convected point sources are also obtained. The results show (in a simple way) how the mean flow affects the radiation pattern from the sources. For convected lateral quadrupoles it causes the exponent of the Doppler factor multiplying the far-field pressure signal to be increased from the value of 3 used by Lighthill to 5.
    Keywords: AERODYNAMICS
    Type: Journal of Fluid Mechanics; 70; Aug. 12
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: The present investigation is an analysis of the radiation from the chemical nonequilibrium region in the shock layer about a vehicle during Venus entry. The radiation and the flow were assumed to be uncoupled. An inviscid, nonequilibrium flowfield was calculated and an effective electronic temperature was determined for the predominant radiating species. Species concentrations and electronic temperature were then input into a radiation transport code to calculate heating rates. The present results confirm earlier investigations which indicate that the radiation should be calculated using electronic temperatures for the radiating species. These temperatures are not related in a simple way to the local translational temperature. For the described mission, the nonequilibrium radiative heating rate is approximately twice the corresponding equilibrium value at peak heating.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 13; Apr. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2011-08-17
    Description: The method presented makes use of a division of the region of integration into closed rectangular elements. The velocity is taken to be constant in each element. The integral equation is reduced to a matrix equation which can be solved by an appropriate iteration approach. The derivation and solution of the matrix equation are discussed and the matrix elements are considered. The described concepts were implemented for a nonlifting parabolic-arc airfoil.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Mar. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2011-08-17
    Description: It is noted that the nonlinear partial differential equation for the perturbation velocity potential and boundary conditions describing steady inviscid compressible transonic flow past a thin two-dimensional airfoil can be transformed into a singular integrodifferential equation and that differentiation of the latter yields an integral equation. Two forms of this integral equation currently exist: one for the singularity that is enclosed in an infinitely long strip of vanishing thickness and the other for the singularity that is enclosed in a vanishing circle. In the present article, a more general integral equation is derived by enclosing the singularity in a vanishing rectangular cavity of arbitrary aspect ratio. The two existing forms of this equation are deduced as special cases distinguished by the respective values for the aspect ratio (infinity for the first form and unity for the second).
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Feb. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: A review is presented of progress in attaining technical objectives in three areas of semiautomatic airfoil development: software, hardware, and applications. Software objectives seek improved mathematical models and computer codes for flow analysis and design optimization for a variety of conditions. The 17-step iterative computer model used in designing the GA (W)-1 airfoil is effective but not yet fully automated; with present methods only single-point computer optimization is possible. Hardware objectives calling for improvement in test facilities and techniques are met in part by the introduction of the Langley (F-3C) wind tunnel for independent evaluation of transonic Mach number and Reynolds effects up to 12-16 million, and by a two-dimensional test section for the Langley 1/3 transonic cryogenic tunnel which will extend the Reynolds number to 50 million. The current status of low-speed, thin, and rotorcraft airfoil development programs is discussed.
    Keywords: AERODYNAMICS
    Type: Astronautics and Aeronautics; 13; Oct. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2011-08-17
    Description: A photoionization technique was used to study flow characteristics in an expansion tunnel. Vertical surveys of the axial component of flow velocity just downstream from the nozzle exit were obtained, and estimates of freestream density were inferred from the velocity measurement technique. The pitot pressure was measured and compared to the average axial component of velocity as a function of time for the two cases when air and CO2 were used as test gases. Vertical velocity and static density profiles at the nozzle exit are presented for the case when CO2 was used as test gas. Experimental results were used to determine the diameter and uniformity of the test core at the nozzle exit and the duration of the quasi-steady flow period. These data are relevant to evaluation of the suitability of operating an expansion tube as an expansion tunnel. The expansion tunnel is an expansion tube with a conical nozzle positioned at the exit of the acceleration section, so that nozzle entrance flow conditions are hypersonic and characterized by hypervelocity.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2011-08-17
    Description: Low Reynolds number flow of an ideal gas over a blunt axisymmetric body of large half-angle at small angles of attack is investigated, for the case of laminar hypersonic flow. Time-varying viscous shock layer equations describing the flowfield are obtained from the full Navier-Stokes system by keeping terms to second order in the inverse square root of Re in both viscous and inviscid regions; the equations are valid for moderate to high Re. Drag, skin friction, and heating rates were obtained at small (or zero) angles of attack. Conditions experienced by planetary entry probes during the high-altitude (early) legs of an atmospheric entry trajectory are pertinent to the problem.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-17
    Description: The paper describes the facilities and test procedures used in a series of wind-tunnel and full-scale flight investigations of the effectiveness of flight spoilers currently existing on wide-bodied transport jet aircraft when used as trailing vortex hazard alleviation devices. Examples of the results of such studies include the variation of trailing wing rolling-moment coefficient with downstream distance behind a B-747 airplane model with various segments of its flight spoilers deflected 45 deg, and comparisons with models without spoilers deflected. It is concluded that the existing flight spoilers on the B-747 are effective as trailing vortex attenuators.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 14; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2011-08-17
    Description: A viscous shock-layer analysis for calculating high energy equilibrium flow fields about blunt axisymmetric bodies is applied to the problem of massive ablation injection with radiation transport. A nongray radiation model is used that accounts for both line and continuum radiation. The solution method is direct and provides both stagnation and downstream solutions. Results for shock heated air show that phenolic-nylon injection is substantially more effective in reducing the wall radiant flux than air injection. Also, for large included body angles, the wall radiative flux and the coupled phenolic-nylon injection rate do not continue to decrease with increasing distance downstream.
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2011-08-17
    Description: A paper by Henderson (1976) provides a method of predicting experimental sphere drag data. This approach uses two equations for the drag coefficient, one for relative Mach number less than one, one for relative Mach number greater than 1.75. For relative Mach numbers between these limits a linear interpolation procedure is followed. In a comment on this paper, it is claimed, on the basis of comparing predictions with experimental results, that a method proposed by Walsh (1975) gives better predictions of the drag coefficient for relative Mach numbers less than 1.75, provided that a modification of the procedure is made for relative Mach numbers less than 0.1. For values over 1.75, both methods are considered equally accurate. In a reply to this comment, it is agreed that the Walsh method is more accurate when Reynolds numbers are within a range between 20 and 200, and Mach numbers are between 0.5 and 1.25. Presumed errors and possible limitations in the Walsh procedure for predicting drag coefficients are discussed.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; June 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2011-08-17
    Description: The vortex lattice method introduced by Lamar and Gloss (1975) was applied to the prediction of subsonic aerodynamic characteristics of hypersonic body-wing configurations. The reliability of the method was assessed through comparison of the calculated and observed aerodynamic performances of two National Hypersonic Flight Research Facility craft at Mach 0.2. The investigation indicated that a vortex lattice model involving 120 or more panel elements can give good results for the lift and induced drag coefficients of the craft, as well as for the pitching moment at angles of attack below 10 to 15 deg. Automated processes for calculating the local slopes of mean-camber surfaces may also render the method suitable for use in preliminary design phases.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 14; Oct. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2011-08-17
    Description: The cooling effectiveness of injection through multiple flush slots at an angle of 10 deg was studied experimentally in a wind tunnel. Air was injected from one to four slots into a turbulent Mach 6 boundary layer. The slot mass flow ratio is defined, and data which describe the dependence of the cooling effectiveness on the slot mass flow ratio are presented. Experimental values are indicated graphically for various cases of single and multiple slot injection, where the total mass injection (i.e., the sum of flow rates from each slot) is the same for each case. The results show that, for a given coolant mass flow rate, thermal protection over the maximum surface area can be accomplished best by injecting the coolant flow through multiple slots.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2011-08-16
    Description: Two hypothetical vortex wakes are introduced and studied theoretically to explore whether the rollup of lift-generated vortex sheets can be suppressed. The circulation distribution across each wake is specified such that one rotates and the other translates as a unit due to their self-induced velocities. Several span loadings are constructed from these solutions and the resulting inviscid wake structure is computed for several span lengths behind the generating wing by use of the discrete vortex method wherein the vortex wake is represented by an array of vortices. The final distribution of vortices is then used to estimate the rolling moment on an encountering wing. It is found that, even though the initial specified motions are not sustained, substantial reductions in rolling moment are predicted for certain ranges of the ratio of the span of the generating wing to the following wing.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 13; Apr. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Publication Date: 2011-08-16
    Description: Analytical solutions for inviscid supersonic corner flows are virtually nonexistent due to the complexity of the interference geometry. In view of this, numerical solutions for swept-compressive and swept-expansive corner flows are obtained. The governing equations are written in strong conservation-law form and are solved iteratively in nonorthogonal conical coordinates by use of a second-order, shock-capturing, finite-difference technique. The computed wave structure and surface pressure distributions are compared with high Reynolds number experimental data and show very good agreement. The results clearly show that supersonic corner flow at reasonably high Reynolds numbers including the effect of sweep is dominated by the inviscid field.
    Keywords: AERODYNAMICS
    Type: Journal of Computational Physics; 17; Feb. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: An investigation was conducted regarding the issue of deviation from two-dimensionality in flowfield studies of a supercritical airfoil. It was found that significant three-dimensional effects occur in transonic airfoil tests, even for an aspect ratio of four. This is especially true at the supercritical Mach numbers, for which lateral propagation of disturbances is effective.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 13; Feb. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 2011-08-16
    Description: The aerodynamic characteristics of the Planetary Atmosphere Experiments Test entry probe were determined experimentally in ballistic range tests over a wide range of Mach and Reynolds numbers, and were compared with full-scale flight results. The ground facility data agreed with the full-scale data within 2 to 3% in drag coefficient, and within 5 to 10% in static stability, at the higher Mach numbers. Comparisons of the flight data with conventional wind-tunnel data indicated a significant disagreement in drag coefficient in the transonic speed range suggestive of important sting or wall interference effects. Variations in drag coefficient with Mach number were very small hypersonically, but variations with Reynolds number were of the order of 15% at a free-stream Mach number of 13 over the Reynolds number range from 10,000 to 1,000,000. Variations in the lift and static-stability curves with Mach number and Reynolds number were also defined.
    Keywords: AERODYNAMICS
    Type: Journal of Spacecraft and Rockets; 12; Jan. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Publication Date: 2011-08-17
    Description: The characteristics of a thick hypersonic boundary layer turbulent for a length of 175 cm on a 4 deg sharp wedge were measured. The resulting boundary layer was free from transverse curvature effects and only mildly affected by upstream history effects caused by pressure and wall temperature gradients. Heat-transfer distributions were used to locate regions of laminar, transitional, and turbulent flow at an edge unit Reynolds number of 470,000 cm at wall-to-total temperature ratios from about 0.3 to 1. Wall cooling had little effect on the location of the transition region. Pitot and total temperature profiles and skin-friction measurements were obtained at several locations along the model longitudinal centerline. Mixing length and turbulent Prandtl number distributions were derived from the fully turbulent mean profiles.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Oct. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2011-08-16
    Description: The paper is concerned with the application of the Murman and Cole (1971) relaxation scheme to steady, inviscid transonic flow problems in two and three dimensions. This scheme, which automatically accounts for weak shock waves, uses separate difference operators in elliptic and hyperbolic regions. The details of the scheme are described in terms of the original small disturbance formulation of Murman and Cole. In particular, Murman's recent (1973) introduction of fully conservative difference operators to obtain the correct shock jumps is examined. The extension to treating the exact isentropic equation is then covered with special attention given to Jameson's (to appear) rotated difference scheme for supersonic flow regions. The bulk of the discussion is related to two-dimensional procedures, and some comparisons with experiment are made, with emphasis on the effects of viscosity and wind-tunnel walls. Application of the Murman-Cole scheme is then discussed for small disturbances in three dimensions.
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2011-08-16
    Description: The paper investigates analytically the effect of multiple slot injection on skin friction for a representative fuselage shape (ogive-cylinder body) and evaluates the potential of slot injection as a drag reduction system in subsonic flow. Typical CTOL cruise flight conditions (Mach number equals 0.82 at altitudes of 11 km) were adopted for a fuselage 67.06 m in length and with maximum diameter of 7.32 m. The numerical method of Price and Harris (1972) was used to calculate the boundary-layer characteristics up to the first slot, while the finite-difference method of Beckwith and Bushnell (1971) was used to calculate the velocity profile downstream of one, three, five, or ten slots. An integral expression is proposed for characterizing skin friction reduction effectiveness, and it is seen that large reductions in viscous drag (50%) are available through slot injection. Skin friction reduction is improved by increasing the number of injection slots but at a diminishing rate.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 12; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2011-08-16
    Description: The investigation reported is concerned with questions regarding a possible Mach number influence on skin friction reduction caused by injection. The investigation shows that data considered by Danberg (1967) for the no-blowing skin friction coefficient are in error. Accurate profiles and local skin friction coefficient values are obtained when the influence of low Reynolds number amplification in the outer region of the boundary layer is included in a calculation method.
    Keywords: AERODYNAMICS
    Type: Journal of Spacecraft and Rockets; 12; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: The paper investigates a two-dimensional oscillating cascade with a subsonic leading edge locus in a supersonic flow. The blades are assumed to be of small thickness and camber, and are undergoing small amplitude-harmonic oscillations. The problem is reduced to the solution of a functional integral equation, and an expression is given for the kernel function.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 13; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2011-08-16
    Description: Results are presented of an experimental investigation on a nonconical wing which supports an attached shock wave over a region of the leading edge near the vertex and a detached shock elsewhere. The shock detachment point is determined from planform schlieren photographs of the flow field and discrepancies are shown to exist between this and the one calculated by applying the oblique shock equations normal to the leading edge. On a physical basis, it is argued that the shock detachment has to obey the two-dimensional law normal to the leading edges. From this, and from other measurements on conical wings, it is thought that the planform schlieren technique may not be particularly satisfactory for detecting shock detachment. Surface pressure distributions are presented and are explained in terms of the flow over related delta wings which are identified as a vertex delta wing and a local delta wing.
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Publication Date: 2011-08-16
    Description: The conical flow solution for axisymmetric supersonic flow past cones has been found to be virtually independent of the ratio of specific heats when normalized in a certain way. A simple rational approximation to this flow is derived. The important singularities and the limiting behavior of the solution are also discussed.
    Keywords: AERODYNAMICS
    Type: Zeitschrift fuer angewandte Mathematik und Physik; 26; July 25
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: A method for designing supersonic inlet contours is described which consists in the interpolation of the contours of two known inlets designed for different Mach numbers, thereby determining the contours for a third inlet at an intermediate design Mach number. Several similar axisymmetric inlet contours were interpolated from known inlets with design Mach numbers ranging from 2.16 to 4.0 and with design Mach numbers differing by as much as 1.0. The flowfields were calculated according to Sorensen's (1965) computer program. Shockwave structure and pressure distribution characteristics are shown for the interpolated inlets. The validity of the interpolation is demonstrated by comparing the plots of the flowfield properties across the throat station of the interpolated inlet with the known inlets which were designed iteratively. It seems possible to write a computer program so that a matrix of known inlet contours can be interpolated.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 12; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-10
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Publication Date: 2011-08-17
    Description: The method of integral relations is extended to general three-dimensional compressible laminar boundary layer flows. The transformation employed to transform the basic three-dimensional compressible boundary layer equations into quasi-incompressible form is an extension of the Howarth transformation. The resulting system of differential equations is integrated numerically by the method of integral relations as proposed by Dorodnitsyn. To demonstrate the accuracy of the method, it is applied to calculation of the parabolic flow over a flat plate and the boundary flow over an infinite yawed cylinder, for which solutions are known. It is then applied to the flow over a flat plate disturbed by a cylinder normal to the plate, for which a finite-difference solution is available for comparison. It is finally applied to calculating the crossflow velocity variation for supersonic flow over a swept wedge.
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-17
    Description: A self-bleeding method for boundary layer control is described and tested for a subsonic inlet designed to operate in the flowfield generated by high angles of attack. Naturally occurring surface static pressure gradients are used to remove the boundary layer from a separation-prone region of the inlet and to reinject it at a less critical location with a net performance gain. The results suggest that this self-bleeding method for boundary-layer control might be successfully applied to other inlets operating at extreme aerodynamic conditions.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 14; Apr. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Publication Date: 2011-08-17
    Description: A flowfield survey was conducted to better define the nature of vehicle forebody flowfield at the inlet location of an airframe-integrated scramjet engine mounted on the lower surface of a high-speed research airplane to be air launched from a B-52 and rocket boosted to Mach 6. The tests were conducted on a 1/30-scale brass model in a Mach-6 20-in. wind tunnel at Reynolds number of 11,200,000 based on distance to engine inlet. Boundary layer profiles at five spanwise locations indicate that the boundary layer in the area of the forebody centerline is more than twice as thick as the boundary layer at three outboard stations. It is shown that the cold streak found in heating contours on the centerline of the forebody is caused by a thickening of the boundary layer on the centerline, and that this thickening decreases with angle of attack.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 14; Apr. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Publication Date: 2011-08-17
    Description: The flow field produced by the intersection of two plane solid surfaces in a supersonic stream is a complex interference flow. These flows can be fully compressive, fully expansive, or of mixed compression-expansion nature. This paper presents a comparison of the experimentally obtained flow-field structure in an axial corner with that predicted numerically by using a shock-capturing finite-difference method. The effect of sweep and surface deflection are evaluated, and the general influence of each is presented for the three classes of corner flow. The results show that the numerical method is a valuable aid in understanding the flow structure for simple configurations. In addition, confidence in the numerical method is gained for use in solving more general three-dimensional configurations where the flow is nonconical and several wave interaction may be presented.
    Keywords: AERODYNAMICS
    Type: British Aircraft Corp.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Publication Date: 2011-08-17
    Description: Linearized theory is used to study the unsteady flow in a supersonic cascade with in-passage shock waves. We use the Wiener-Hopf technique to obtain a closed-form analytical solution for the supersonic region. To obtain a solution for the rotational flow in the subsonic region we must solve an infinite set of linear algebraic equations. The analysis shows that it is possible to correlate quantitatively the oscillatory shock motion with the Kutta condition at the trailing edges of the blades. This feature allows us to account for the effect of shock motion on the stability of the cascade. Unlike the theory for a completely supersonic flow, the present study predicts the occurrence of supersonic bending flutter. It therefore provides a possible explanation for the bending flutter that has recently been detected in aircraft-engine compressors at higher blade loadings.
    Keywords: AERODYNAMICS
    Type: Journal of Fluid Mechanics; 83; Dec. 5
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Publication Date: 2011-08-17
    Description: A correlation of new turbulent two-dimensional data and peak heating data for attaching free shear layers is presented for a 2.54-cm and 5.08-cm diam cylindrical leading-edge slab 25.4 cm long, and 7.62 and 10.16 cm wide. A 30.48 x 25.4 cm sharp leading-edge flat plate set at 15 and 20 deg is used to generate plane impinging shocks. The freestream Mach number is 6 and the freestream Reynolds number varies from 3,300,000 to 25,600,000/m. Peak heating is measured on silica-based epoxy models with a phase change coating technique. A comparison of the free shear layer data with the transition data of Birch and Keyes (1972) reveals that the shear layer data are turbulent at attachment. The trend of the data shows that peak heating is strongly affected by the state of development at attachment. As the free shear layers become more fully developed, the data approach the two-dimensional correlation. Persistence of transitional flow structures for supersonic free shear flows is pointed out.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 15; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 2011-08-17
    Description: The present analysis was carried out to estimate the heating levels of the external nozzle of a scramjet/airframe-integrated research aircraft. A parametric examination of the effects of Mach number, reference length, and wall temperature showed that the heating rate distributions are independent of reference length and wall temperature. The initial heating rates obtained for a Mach 6 flight are in the (3 to 8) x 10 to the 5th power W/sq m range. Underlying the entire study is the question of nozzle boundary layer formation and growth, as well as the question of the reference length value that should be used in the computations. It is shown that the reference length is not the dominant factor setting the heating levels; an attempt to bound the actual length was made. A more detailed calculation of the rates requires further work to gain a better understanding of the combustor exit boundary layer.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft; 14; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: The paper sets forth in detail a method for the finite-difference computation of three-dimensional supersonic fields in an Eulerian mesh. First-, second-, and third-order finite difference schemes are examined. Attention is given to proper treatment of the impermeable and permeable boundaries encompassing the computational plane. Numerical results are presented for certain specific configurations: a conical wing-body combination, internal corner flow, a two-dimensional blunt body, an interfering shock problem, and three-dimensional inviscid supersonic flow past a shuttle-orbiter type vehicle.
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-16
    Description: Accurate semianalytic solutions to the inverse blunt-body problem have been obtained using a method of series expansion. Rational fractions are employed for series summation and analytic continuation. Angles of incidence up to 30 deg and Mach numbers as low as 2 have been considered. The maximum-entropy streamline will not wet the body surface in asymmetric flow. It may pass either above or below the stagnation streamline. Limit lines appear in the supersonic portion of the flow field, both in the shock layer and in its upstream analytic continuation.
    Keywords: AERODYNAMICS
    Type: Physics of Fluids; 18; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 2011-08-16
    Description: The paper reviews the experimental data on the incipient separation characteristics of planar delta wings of 75 degree sharp leading edges, with full-span trailing edge flap deflected into the windward flow. The local Reynolds number range for these investigations covered laminar, transitional and turbulent conditions. It is shown that, while turbulent boundary layer data correlates with two dimensional results, in the laminar and transitional cases, there is a nearly parallel shift to higher flap angles for incipient separation.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 13; Oct. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2011-08-16
    Description: A forward-marching procedure for separated boundary-layer flows which permits the rapid and accurate solution of flows of limited extent is presented. The streamwise convection of vorticity in the reversed flow region is neglected, and this approximation is incorporated into a previously developed (Carter, 1974) inverse boundary-layer procedure. The equations are solved by the Crank-Nicolson finite-difference scheme in which column iteration is carried out at each streamwise station. Instabilities encountered in the column iterations are removed by introducing timelike terms in the finite-difference equations. This provides both unconditional diagonal dominance and a column iterative scheme, found to be stable using the von Neumann stability analysis.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 13; Aug. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2012-05-22
    Description: Afterbody drag predictions for jet aircraft are usually made experimentally with the jet exhaust flow simulated. The physical gas properties of the fluid used for the model jet exhaust can affect the accuracy of simulation of the airplane's jet exhaust plume. The effect of the accuracy of this simulation on afterbody drag was investigated by wind-tunnel tests with single engine model. In addition to unheated air as the exhaust gas, the decomposition products of three different concentrations of hydrogen peroxide were utilized. The air jet simulation consistently resulted in higher boattail drag than hydrogen peroxide simulation. The differences in drag for the various exhaust gases are attributed to different plume shapes and entrainment properties of the gases. The largest differences in drag due to exhaust gas properties were obtained for the combination of high transonic Mach numbers and high boattail angles. For these conditions, the current data indicate that the use of air to simulate a nonafterburning turbojet exhaust can result in an increase in afterbody amounting to 20 percent of the nonafterburning turbojet value.
    Keywords: AERODYNAMICS
    Type: AGARD Airframe(Propulsion Interference; 11 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 2012-05-22
    Description: A family of nacelle mounted high angle boattail nozzles was tested to investigate Reynolds number effects on drag. The nozzles were flown on a modified F-106B and mounted on scale models of an F-106 in a wind tunnel. A 19- to 1-range of Reynolds number was covered as a result of the large size differences between models and by flying over a range of altitude. In flight the nozzles were mounted behind J-85 turbojet engines. Jet boundary simulators and a powered turbojet engine simulator were used on the wind tunnel models. Data were taken at Mach numbers of 0.6 and 0.9. Boattail drag was found to be affected by Reynolds number. The effect is a complex relationship dependent upon boundary layer thickness and nozzle boattail shape. As Reynolds number was increased from the lowest values obtained with scale models, boattail drag first increased to a maximum at the lowest flight Reynolds number and then decreased.
    Keywords: AERODYNAMICS
    Type: AGARD Airframe(Propulsion Interference; 15 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2011-08-17
    Description: An overview is presented of the aerodynamic inputs required for analysis of flight dynamics in the high-angle-of-attack regime wherein large-disturbance, nonlinear effects predominate. An outline of the presentation is presented. The discussion includes: (1) some important fundamental phenomena which determine to a large extent the aerodynamic characteristics of airplanes at high angles of attack; (2) static and dynamic aerodynamic characteristics near the stall; (3) aerodynamics of the spin; (4) test techniques used in stall/spin studies; (5) applications of aerodynamic data to problems in flight dynamics in the stall/spin area; and (6) the outlook for future research in the area.
    Keywords: AERODYNAMICS
    Type: Von Karman Inst. for Fluid Dyn. Aerodyn. Inputs for Probl. in Aircraft Dyn., Vol. 2; 39 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Publication Date: 2011-08-18
    Keywords: AERODYNAMICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Publication Date: 2016-06-07
    Description: Flight tests evaluating the effects of altered span loading, turbulence ingestion, combinations of mass and turbulence ingestion, and combinations of altered span loading turbulance ingestion on trailed wake vortex attenuation were conducted. Span loadings were altered in flight by varying the deflections of the inboard and outboard flaps on a B-747 aircraft. Turbulence ingestion was achieved in flight by mounting splines on a C-54G aircraft. Mass and turbulence ingestion was achieved in flight by varying the thrust on the B-747 aircraft. Combinations of altered span loading and turbulence ingestion were achieved in flight by installing a spoiler on a CV-990 aircraft and by deflecting the existing spoilers on a B-747 aircraft. The characteristics of the attenuated and unattenuated vortexes were determined by probing them with smaller aircraft. Acceptable separation distances for encounters with the attenuated and unattenuated vortexes are presented.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 369-403
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Publication Date: 2016-06-07
    Description: To determine the feasibility of altering the formation and decay of aircraft trailing vortexes through aerodynamic means, the test capabilities of two wind tunnels and two towing basins were used. The facilities, common models, and measurement techniques that were employed in the evaluation of vortex minimization concepts are described.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 129-156
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: A simple aerodynamic bending moment envelope is derived for conventionally shaped airships. This criterion is intended to be used, much like the Naval Architect's standard wave, for preliminary estimates of longitudinal strength requirements. It should be useful in tradeoff studies between speed, fineness ratio, block coefficient, structure weight, and other such general parameters of airship design.
    Keywords: AERODYNAMICS
    Type: MIT Proc. of the Interagency Workshop on Lighter than Air Vehicles; p 169-176
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 2016-06-07
    Description: A historical view of multi-jet engine installations is given that emphasizes integration of the powerplant and the airframe in aircraft design for improved reduction in external nacelle drag and interference drag characteristics.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 235-244
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Publication Date: 2016-06-07
    Description: The analytical prediction and description of transonic flow in turbomachinery is complicated by three fundamental effects: (1) the fluid equations describing the transonic regime are inherently nonlinear, (2) shock waves may be present in the flow, and (3) turbomachine blading is geometrically complex, possessing large amounts of curvature, stagger, and twist. A three-dimensional computation procedure for the study of transonic turbomachine fluid mechanics is described. The fluid differential equations and corresponding difference operators are presented, the boundary conditions for complex blade shapes are described, and the computational implementation and mapping procedures are developed. Illustrative results of a typical unthrottled transonic rotor are also presented.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 567-585
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 2016-06-07
    Description: A code developed for simulating high Reynolds number transonic flow fields of arbitrary configuration is described. This code, in conjunction with laboratory experiments, is used to devise and test turbulence transport models which may be suitable in the prediction of such flow fields, with particular emphasis on regions of flow separation. The solutions describe the flow field, including both the shock-induced and trailing-edge separation regions, in sufficient detail to provide the profile and friction drag.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 419-436
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Publication Date: 2016-06-07
    Description: A method is developed for solving the laminar and turbulent compressible boundary-layer equations for separating and reattaching flows. Results of this method are compared with experimental data for two laminar and three turbulent boundary-layer, shock-wave interactions. Several Navier-Stokes solutions were obtained for each of the laminar boundary-layer, shock-wave interactions considered. Comparison of these solutions indicates a first-order sensitivity in C sub f to the computational mesh selected in both the viscous and inviscid portions of the flow.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 151-175
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Publication Date: 2016-06-07
    Description: Data presented indicate that the wing-mounted spline is a effective vortex-attenuating device. A comparison of the vortex induced rolling moment results at a separation scale distance of 0.70 km with those measured in full scale flight indicate good agreement for the unattenuated vortex configuration. The comparison also indicates that the spline effectiveness in flight was greater than in the ground facility test. The results of an applications study show that, for the heavy commercial jet aircraft studied, use of the splines does result in some degradation of the climb gradient and rate of climb, but the aircraft should meet certification requirements.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 271-303
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Publication Date: 2016-06-07
    Description: The theory and use of a laser velocimeter that makes simultaneous measurements of vertical and longitudinal velocities while rapidly scanning a flow field laterally are described, and its direct application to trailing wake-vortex research is discussed. Pertinent measurements of aircraft wake-vortex velocity distributions obtained in a wind tunnel and water towing tank are presented. The utility of the velocimeter to quantitatively assess differences in wake velocity distributions due to wake dissipating devices and span loading changes on the wake-generating model is also demonstrated.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 157-192
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Publication Date: 2016-06-07
    Description: The inviscid, internal, and external axial corner flows generated by two intersecting wedges traveling supersonically are obtained by use of a second-order shock-capturing, finite-difference approach. The governing equations are solved iteratively in conical coordinates to yield the complicated wave structure of the internal corner and the simple peripheral shock of the external corner. The numerical results for the internal flows compare favorably with existing experimental data.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 643-658
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Publication Date: 2016-06-07
    Description: A numerical method for solving the parabolic approximation to the steady-state compressible Navier-Stokes equations is examined. The approximation neglects only the streamwise gradients of shear stress. An implicit finite difference method is used which advances the solution downstream from an initial data surface and determines the complete viscous-inviscid flow between the body and bow shock wave. It is necessary that the inviscid portion of the flow field be supersonic. Crossflow separation is determined as part of the solution. The method is applied to a 15 deg sphere-cone at 15 deg angle of attack, and the results are compared with an inviscid method-of-characteristics calculation.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 531-542
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Publication Date: 2016-06-07
    Description: A previous analysis of fluid filled storage bags is extended to the case of a long fluid filled cylindrical membrane supported by uniform line loads. Cross-sectional shape, stiffness of the support system and stress resultants in the membrane are determined. The application of the numerical results to problems arising in the design of nonrigid airships is discussed.
    Keywords: AERODYNAMICS
    Type: MIT Proc. of the Interagency Workshop on Lighter than Air Vehicles; p 199-208
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: The forces and moments acting upon a LTA vehicle are considered in order to develop parameters describing planar motion. Similar expressions for HTA vehicles will be given to emphasize the greater complexity of aerodynamic effects when buoyancy effects cannot be neglected. A brief summary is also given of the use of virtual mass coefficients to calculate loads on airships.
    Keywords: AERODYNAMICS
    Type: MIT Proc. of the Interagency Workshop on Lighter than Air Vehicles; p 177-186
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: The state-of-the-art on aerodynamic drag reduction is briefly reviewed. The various elements making up the total drag of an aircraft include fuselage, wing, nacelles, trim, interference, tail, and cooling drag.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 11-37
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 2016-06-07
    Description: A number of drag items are related to the performance of a complete aircraft configuration. First, the effect of fuselage camber, wing and nacelle incidence are discussed from a viewpoint of design decision making. Second, the effect of overall cruise drag on the design gross and empty weight of the airplane is discussed. Examples show that cruise drag can have a very important influence on total airplane weight. Third, the effects of usable cruise lift-to-drag ratio and wing loading are shown to be important. Finally several research needs relating to design of the complete configuration are reviewed.
    Keywords: AERODYNAMICS
    Type: Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 337-351
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Munk's stagger theorem holds that the induced drag of a multiplane is independent of the streamwise position (the stagger) of its lifting elements so long as the gap/span ratios and the element/element lift ratios are specified. In particular, a monoplane-tailplane or a monoplane-foreplane (canard)arrangement can be regarded as a biplane of zero gap and the trim drag due to tailplane download or foreplane upload can be readily calculated. The trim drag penalty is the same for both configurations. Relations are given for trim drag estimates for various practical arrangements.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 319-329
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Optimization of L/D through minimizing induced drag through a detailed flow study together with force, pressure and vorticity measurements is considered. Flow visualization with neutral helium bubbles provides an excellent means of observing the effects of configuration changes.
    Keywords: AERODYNAMICS
    Type: Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 215-233
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Publication Date: 2016-06-07
    Description: Most fuselage geometries cover a portion of the wing leading edge near the plane of symmetry, and it seems reasonable to expect that a large fraction of the leading edge suction which would be developed by the covered wing at high angles of attack is not developed on the fuselage. This is one of the reasons that the Oswald span efficiency factor for the wing body combination fails to approach the value predicted by lifting line theory for the isolated wing. Some traditional and recent literature on wing-body interference is discussed and high Reynolds number data on wing-body-nacelle drag are reviewed. An exposed central leading edge geometry has been developed for a sailplane configuration. Low Reynolds number tests have not validated the design concept.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 107-115
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 2016-06-07
    Description: Analytical drag methods and wind tunnel evaluation of aircraft design features are used to identify excessive drag of general aviation aircraft with reciprocating engines.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 39-41
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Publication Date: 2016-06-07
    Description: This summary of drag results presents tabulations on fighter aircraft and light twin general aviation aircraft wind tunnel tests. The figures show that the friction drag for light twins is larger than that for the fighters because of the greater wetted area and the smaller wing area used for reference. Full scale tunnel tests developed the following design features contributing to excessive drag: cooling flow system, engine exhaust stacks, landing gears, control surface gaps, and wing irregularities and leakages.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 43-60
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Publication Date: 2016-06-07
    Description: The status of an investigation of four numerical techniques for the time-dependent compressible Navier-Stokes equations is presented. Results for free shear layer calculations in the Reynolds number range from 1000 to 81000 indicate that a sequential alternating-direction implicit (ADI) finite-difference procedure requires longer computing times to reach steady state than a low-storage hopscotch finite-difference procedure. A finite-element method with cubic approximating functions was found to require excessive computer storage and computation times. A fourth method, an alternating-direction cubic spline technique which is still being tested, is also described.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 437-468
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Publication Date: 2016-06-07
    Description: A review is given of recent advances in two distinct computational methods for evaluating turbulence fields, namely, statistical Reynolds stress modeling and turbulence simulation, where large eddies are followed in time. It is shown that evaluation of the mean Reynolds stresses, rather than use of a scalar eddy viscosity, permits an explanation of streamline curvature effects found in several experiments. Turbulence simulation, with a new volume averaging technique and third-order accurate finite-difference computing is shown to predict the decay of isotropic turbulence in incompressible flow with rather modest computer storage requirements, even at Reynolds numbers of aerodynamic interest.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 317-339
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Publication Date: 2016-06-07
    Description: Numerical solutions are presented for the laminar and turbulent boundary-layer equations for incompressible flows with separation and reattachment. The separation angularity is avoided by using an inverse technique in which the displacement thickness is prescribed and the pressure is deduced from the resulting solution. The turbulent results appear qualitatively correct despite the use of a two-layer eddy-viscosity model which is generally assumed appropriate only for mild-pressure-gradient flows. A new viscous-inviscid interaction technique is presented in which the inviscid flow is solved inversely by prescribing the pressure from the boundary-layer solution and deducing the new displacement thickness from the solution of a Cauchy integral. Calculations are presented using this interaction procedure for a laminar flow in which separation and reattachment occur on a solid surface.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 125-150
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Publication Date: 2016-06-07
    Description: Shock-capturing solutions for an axisymmetric supersonic inlet at small angles of attack are obtained. Good overall agreement between the shock-capturing solutions and experimental data is shown except in regions of strong viscous effects or boundary-layer removal. Although the results indicate a strong potential for the use of shock-capturing or finite-difference solutions for internal flows, improvement in the ability to handle the reflection of strong shockwaves having downstream Mach numbers near 1 is needed.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 623-642
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 2017-10-02
    Description: A critical analysis of available wall data which indicated drag reduction under turbulent boundary layers. Detailed structural dynamic calculations suggest the surfaces responded in a resonant, rather than compliant, manner. Alternate explanations are given for drag reductions observed in two classes of experiments: flexible pipe flown, and waterbacked membranes in air. Analysis indicates the wall motion for the remaining data is typified by short wave lengths in agreement with the requirement of a possible compliant wall drag reduction mechanism recently suggested by Langley.
    Keywords: AERODYNAMICS
    Type: AGARD Spec. Course on Concepts for Drag Reduction; 26 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2017-10-02
    Description: The results of repeat experimental research on methods for reducing subsonic drag due to lift are discussed. The NASA supercritical airfoils and their application to structurally practical wings with increased aspect radio are described. A design approach and experimental results for wing-tip-mounted winglets are presented. Several methods for utilizing the thrust of jet engines to provide reductions in the drag due to lift are also discussed.
    Keywords: AERODYNAMICS
    Type: AGARD Spec. Course on Concepts for Drag Reduction; 17 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Publication Date: 2017-10-02
    Description: An implicit finite difference procedure was developed for the efficient solution of unsteady transonic flow fields. Sample computations illustrate applications of procedures to aerodynamic problems. Solutions are presented that illustrate three types of shock wave motion that can result from airfoil control surface oscillations. The significant effect of wind tunnel wall conditions on these shock wave motions is demonstrated. Solutions are also presented for a simple aeroelastic problem in which the flow field equations and the structural motion equations are integrated simultaneously in time. Both stable and unstable aeroelastic interactions are considered. The procedure is adapted to compute unsteady aerodynamic force coefficients by the indicial method.
    Keywords: AERODYNAMICS
    Type: AGARD Unsteady Airloads in Separated and Transonic Flow; 11 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Publication Date: 2017-10-02
    Description: An assessment of the applicability of four loading prediction methods to high angle-of-attack conditions for simplified wing-body configurations is provided. The methods are: The tangent wedge approximation, the linear theory methods of Middleton and Woodward, and a shock-fitting finite-difference technique. Estimates obtained by these methods were compared with experimental pressure data on delta wings to examine the effects of Mach number, camber, sweep angle, and angle of attack. Results indicate that all of the methods provided reasonable estimates at moderate angles of attack. At these moderate angles of attack, the methods of Middleton and Woodward provided good estimates at Mach numbers higher than those usually associated with linear theory. Only the finite-difference method provided reasonable load estimates at high angles of attack.
    Keywords: AERODYNAMICS
    Type: AGARD Prediction of Aerodynamic Loading; 7 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Publication Date: 2017-10-02
    Description: A wind tunnel test of an arrow wing body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control surface deflection, has been conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions have been made using current state-of-the-art attached- and separated-flow methods. The purpose of these comparisons was to delineate conditions under which these theories are valid for aeroelastic calculations and to explore the use of empirical methods to correct the theoretical methods where theory is deficient. It was determined that current state-of-the-art attached flow and empirical methods were inadequate to predict aeroelastic loads for this configuration.
    Keywords: AERODYNAMICS
    Type: AGARD Prediction of Aerodynamic Loading; 14 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: A survey is presented of inviscid theoretical methods that are useful in the study of lift-generated vortices. Concepts derived using these invisicid theories are cited which have helped to guide research directed at alleviating the velocities and rolling moments imposed on aircraft entering these wakes.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 9-60
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 2016-06-07
    Description: A very general method for calculating compressible three-dimensional laminar and turbulent boundary layers on arbitrary wings is described. The method utilizes a nonorthogonal coordinate system for the boundary-layer calculations and includes a geometry package that represents the wing analytically. In the calculations all the geometric parameters of the coordinate system are accounted for. The Reynolds shear-stress terms are modeled by an eddy-viscosity formulation developed by Cebeci. The governing equations are solved by a very efficient two-point finite-difference method used earlier by Keller and Cebeci for two-dimensional flows and later by Cebeci for three-dimensional flows.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 41-76
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 2019-05-30
    Description: Flow spoiler and aerodynamic balance effects on oscillating hinge moments for swept fin-rudder combination in transonic wind tunnel
    Keywords: AERODYNAMICS
    Type: NACA-RM-L58C28
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Publication Date: 2019-05-24
    Description: Movable tail surface for aircraft control without flutter using X-15 scale model at hypersonic speed
    Keywords: AERODYNAMICS
    Type: NACA-RM-L58B27
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Publication Date: 2019-05-24
    Description: An investigation has been made at Mach numbers of 1.61 and 2.01 and Reynolds numbers of 1.7 x l0(exp 6) and 3.6 x l0(exp 6) to determine the pressure distributions over a swept wing with a series of 14 control configurations. The wing had 40 deg of sweep of the quarter-chord line, an aspect ratio of 3.1, and a taper ratio of 0.4. Measurements were made at angles of attack from 0 deg to +/- 15 deg for control deflections from -60 deg to 60 deg. This report contains tabulated pressure data for the complete range of test conditions.
    Keywords: AERODYNAMICS
    Type: NACA-RM-L57H30
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Publication Date: 2019-05-23
    Description: Factors affecting static, longitudinal, and directional stability characteristics of supersonic aircraft configurations
    Keywords: AERODYNAMICS
    Type: NACA-RM-L57E24A
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Publication Date: 2019-05-23
    Description: Supersonic wind tunnel test of underslung scoop inlet on body of revolution
    Keywords: AERODYNAMICS
    Type: NACA-RM-E56L11
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Publication Date: 2019-05-23
    Description: Supersonic wind tunnel test of twin-duct variable geometry side inlets
    Keywords: AERODYNAMICS
    Type: NACA-RM-E56K15
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Publication Date: 2019-05-23
    Description: An investigation of the aerodynamic characteristics of several hypersonic missile configurations with various canard controls for an angle-of-attack range from 0 deg to about 28 deg at sideslip angles of about 0 deg and 4 deg at a Mach number of 2.01 has been made in the Langley 4- by 4-foot supersonic pressure tunnel. The configurations tested we re a body alone which had a ratio of length to diameter of 10, the b ody with a 10 deg flare, the body with cruciform fins of 5 deg or 15 deg apex angle, and a flare-stabilized rocket model with a modified Von Karman nose. Various canard surfaces for pitch control only were te sted on the body with the 10 deg flare and on the body with both sets of fins. The results indicated that the addition of a flared afterbody or cruciform fins produced configurations which were longitudinally and directionally stable. The body with 5 deg fins should be capable of producing higher normal accelerations than the flared body. A l l of the canard surfaces were effective longitudinal controls which produced net positive increments of normal force and pitching moments which progressively decreased with increasing angle of attack.
    Keywords: AERODYNAMICS
    Type: NACA-RM-L58A21
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Publication Date: 2019-05-23
    Description: Internal aerodynamics and performance of clustered jet-exit installations at transonic speeds
    Keywords: AERODYNAMICS
    Type: NACA-RM-L58E01
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2015-11-05
    Description: Results indicating that unsteady aerodynamic loads derived under the assumption of simple harmonic motions executed by airfoil or wing can be extended to arbitrary motions are summarized. The generalized Theodorsen (1953) function referable to loads due to simple harmonic oscillations of a wing section in incompressible flow, the Laplace inversion integral for unsteady aerodynamic loads, calculations of root loci of aeroelastic loads, and analysis of generalized compressible transient airloads are discussed.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; Volume 15; Apr. 1977
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Publication Date: 2016-06-07
    Description: Results are presented of groundbased and flight investigations performed to develop spoilers as trailing vortex alleviation devices. Based on the results obtained in these investigations, it was found that the induced rolling moment on a trailing model can be reduced by spoilers located near the midsemispan of a vortex generating wing. Substantial reductions in induced rolling moment occur when the spoiler vortex attenuator is located well forward on both unswept and swept wing models. In addition, it was found that existing flight spoilers on the jumbo-jet transport aircraft can be effective as trailing vortex attenuators.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 339-368
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Publication Date: 2016-06-07
    Description: Exploratory concepts are described which were investigated to achieve a reduction in the vortex induced rolling upsets produced by heavy aircraft trailing vortexes. The initial tests included the use of mass injection, oscillating devices, wingtip shape design, interacting multiple vortexes, and end plates. Although later refinements of some of these concepts were successful, initial test results did not indicate a capability of these concepts to significantly alter the vortex induced rolling upset on a following aircraft.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 221-250
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Publication Date: 2016-06-07
    Description: Flight test techniques developed for use in a study of wake turbulence and used recently in flight studies of wake minimization methods are discussed. Flow visualization was developed as a technique for qualitatively assessing minimization methods and is required in flight test procedures for making quantitative measurements. The quantitative techniques are the measurement of the upset dynamics of an aircraft encountering the wake and the measurement of the wake velocity profiles. Descriptions of the instrumentation and the data reduction and correlation methods are given.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 193-220
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Publication Date: 2016-06-07
    Description: A survey was made of research on the alleviation of the trailing vortex hazard by altering span loading with flaps on the generator airplane. Flap configurations of the generator that shed multiple vortices were found to have wakes that dispersed by vortex merging and sinusoidal instability. Reductions of approximately 50 percent in both the wake rolling moment imposed on a following aircraft and the aircraft separation requirement were achieved in the ground based and flight test experiments by deflecting the trailing edge flaps more inboard than outboard. Significantly, this configuration did not increase the drag or vibration on the generating aircraft compared to the conventional landing configuration. Ground based results of rolling moment measurement and flow visualization are shown, using a water tow facility, an air tow facility, and a wind tunnel. Flight test results are also shown, using a full scale B-747 airplane. General agreement was found among the results of the various ground based facilities and the flight tests.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 305-338
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Publication Date: 2016-06-07
    Description: An experimental investigation was conducted to determine the vortex attenuating effect of engine thrust. Tests were made using a 0.03-scale model of the Boeing 747 transport aircraft as a vortex generating model. A Learjet-class probe model was used to measure the vortex induced rolling moment at a scale separation distance of 1.63 km. These tests were conducted at a lift coefficient of 1.4 at a model velocity of 30.48 m/s. The data presented indicate that engine thrust is effective as a vortex attenuating device when the engines are operated at high thrust levels and are positioned to direct the high energy engine wake into the core of the vortex. The greatest thrust vortex attenuation was obtained by operating the inboard engine thrust reversers at one-quarter thrust and the outboard engines at maximum forward thrust.
    Keywords: AERODYNAMICS
    Type: Wake Vortex Minimization; p 251-270
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Publication Date: 2016-06-07
    Description: A numerical method is presented which is valid for integration of the parabolic-elliptic Navier-Stokes equations. The solution procedure is applied to the three-dimensional supersonic flow of a jet issuing into a supersonic free stream. Difficulties associated with the imposition of free-stream boundary conditions are noted, and a coordinate transformation, which maps the point at infinity onto a finite value, is introduced to alleviate these difficulties. Results are presented for calculations of a square jet and varying-aspect-ratio rectangular jets. The solution behavior varies from axisymmetry for the square jet to nearly two-dimensional for the high-aspect-ratio rectangle, although the computation always calculates the flow as though it were truly three-dimensional.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 543-565
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Publication Date: 2016-06-07
    Description: Numerical solutions of the complete, time-averaged conservation equations using several eddy-viscosity models for the Reynolds shear stress to close the equations are compared with experimental measurements in a compressible, turbulent separated flow. An efficient time-splitting, explicit difference scheme was used to solve the two-dimensional conservation equations. The experiment used for comparison was a turbulent boundary layer that was separated by an incident shock wave in a Mach 2.93 flow with a unit Reynolds number of 5.7 x 10 to the seventh power m. Comparisons of predicted and experimental values of surface pressure, shear stress along the wall, and velocity profiles are shown. One of the tested eddy-viscosity models which allows the shear stress to be out of equilibrium with the mean flow produces substantially better agreement with the experimental measurements than the simpler models. A tool is thereby provided for inferring additional information about the flow, such as static pressures in the stream, which might not be directly obtainable from experiments.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 401-417
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Publication Date: 2016-06-07
    Description: It is shown that disturbances in external flow can significantly affect, by as much as an order of magnitude, the turbulent mixing rate in free shear layers and that the length scale of the external flow disturbances is as important as the amplitude. The difference between the effect of wide-band and narrow-band disturbances is stressed. The model for pressure fluctuation term in the kinetic energy equation is included in a two-equation model. The reduced spreading rate in high Mach number, high Reynolds number, adiabatic, free turbulent shear layers is predicted.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 341-376
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: Tail size requirement calculations are presented for a vertical tail performing a coordinated turn reversal at corresponding load requirements with minimum tail drag.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 43-446
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2016-06-07
    Description: A discussion of data of and methods for predicting trim drag is presented. Specifically the following subjects are discussed: (1) economic impact of trim drag; (2) the trim drag problem in propeller driven airplanes and the effect of propeller and nacelle location; (3) theoretical procedures for predicting trim drag; and (4) research needs in the area of trim drag.
    Keywords: AERODYNAMICS
    Type: Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 295-305
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Publication Date: 2016-06-07
    Description: Modifications are proposed to standard estimating procedures, as well as the BODY computer program, which predict that the drag of two nacelles will equal the drag of the fuselage. A preliminary computer analysis that considers increased dimensions for the nacelle forebody so that the noise is relatively less blunt indicates a reduction in form drag much greater than the increase in skin friction drag attributable to increased surface area.
    Keywords: AERODYNAMICS
    Type: Kansas Univ. Proc. of the NASA, Ind., Univ., Gen. Aviation Drag Reduction Workshop; p 257-261
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Publication Date: 2016-06-07
    Description: Three-dimensional unsteady transonic flow through an axial turbomachine stage is described in terms of a pair of two-dimensional formulations pertaining to orthogonal surfaces, namely, a blade-to-blade surface and a hub-to-casing surface. The resulting systems of nonlinear, inviscid, compressible equations of motion are solved by an explicit finite-difference technique. The blade-to-blade program includes the periodic interaction between rotor and stator blade rows. Treatment of the boundary conditions and of the blade slipstream motion by a characteristic type procedure is discussed in detail. Harmonic analysis of the acoustic far field produced by the blade row interaction, including an arbitrary initial transient, is outlined. Results from the blade-to-blade program are compared with experimental measurements of the rotating pressure field at the tip of a high-speed fan. The hub-to-casing program determines circumferentially averaged flow properties on a meridional plane. Blade row interactions are neglected in this formulation, but the force distributions over the entire blade surface for both the rotor and stator are obtained. Results from the hub-to-casing program are compared with a relaxation method solution for a subsonic rotor. Results are also presented for a quiet fan stage which includes transonic flow in both the rotor and stator and a normal shock in the stator.
    Keywords: AERODYNAMICS
    Type: Aerodynamic Analyses Requiring Advanced Computers, Pt. 1; p 587-621
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...