ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1
    facet.materialart.
    Unknown
    Computational investigation of a pneumatic forebody flow control concept (1993)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 30; 3; p. 326-333.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    High alpha aerodynamic control by tangential fuselage blowing (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: This work explores the effect of tangential blowing on the vortical structures that develop around a tangent-ogive cylinder configuration at high angle of attack. A lateral force results if blowing is applied asymmetrically. The study is conducted numerically by solving the three-dimensional, compressible-flow Navier-Stokes equations. The computation was done for a Reynolds number of 52,000, Mach number of 0.2, blowing momentum coefficients of 0.0, 0.1, 0.2, and 0.4, and angle of attack of 10, 30, and 45 deg. Only asymmetrical blowing was considered. Surface streamlines, helicity contours and pressure distributions are obtained for each case.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 91-0620
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    A computational study of thrust augmenting ejectors based on a viscous-inviscid approach (1987)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A viscous-inviscid interaction technique is advocated as both an efficient and accurate means of predicting the performance of two-dimensional thrust augmenting ejectors. The flow field is subdivided into a viscous region that contains the turbulent jet and an inviscid region that contains the ambient fluid drawn into the device. The inviscid region is computed with a higher-order panel method, while an integral method is used for the description of the viscous part. The strong viscous-inviscid interaction present within the ejector is simulated in an iterative process where the two regions influence each other en route to a converged solution. The model is applied to a variety of parametric and optimization studies involving ejectors having either one or two primary jets. The effects of nozzle placement, inlet and diffuser shape, free stream speed, and ejector length are investigated. The inlet shape for single jet ejectors is optimized for various free stream speeds and Reynolds numbers. Optimal nozzle tilt and location are identified for various dual-ejector configurations.
    Keywords: AIRCRAFT PROPULSION AND POWER
    Type: NASA-CR-181205 , NAS 1.26:181205 , JIAA-TR-77
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Pneumatic vortical flow control at high angles of attack (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The injection of thin, high-momentum jets of air into the fuselage forebody boundary layers of the F-18 aircraft is explored numerically as a means of controlling the onset of fuselage vortices and of generating yaw control forces. The study was carried out for an angle of attack of 30 deg with symmetrical and asymmetrical blowing configurations. One-sided blowing results in a strongly asymmetrical flow pattern in the fore portion of the fuselage, leading to a net lateral force.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 90-0098
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Numerical study of delta wing leading edge blowing (1988)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Spanwise and tangential leading edge blowing as a means of controlling the position and strength of the leading edge vortices are studied by numerical solution of the three-dimensional Navier-Stokes equations. The leading edge jet is simulated by defining a permeable boundary, corresponding to the jet slot, where suitable boundary conditions are implemented. Numerical results are shown to compare favorably with experimental measurements. It is found that the use of spanwise leading edge blowing at moderate angle of attack magnifies the size and strength of the leading edge vortices, and moves the vortex cores outboard and upward. The increase in lift primarily comes from the greater nonlinear vortex lift. However, spanwise blowing causes earlier vortex breakdown, thus decreasing the stall angle. The effects of tangential blowing at low to moderate angles of attack tend to reduce the pressure peaks associated with leading edge vortices and to increase the suction peak around the leading edge, so that the integrated value of the surface pressure remains about the same. Tangential leading edge blowing in post-stall conditions is shown to re-establish vortical flow and delay vortex bursting, thus increasing C sub L sub max and stall angle.
    Keywords: AERODYNAMICS
    Type: NASA-CR-183101 , NAS 1.26:183101 , JIAA-TR-86
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Numerical study of the effect of tangential leading edge blowing on delta wing vortical flow (1989)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: A numerical simulation of tangential blowing along the leading edge of a delta wing is analyzed as a means of controlling the position and strength of the leading-edge vortices. The computation is done by numerical solutions of the three-dimensional thin-layer Navier-Stokes equations. Numerical results are shown to compare favorably with experimental measurements. It is found that the use of tangential leading-edge blowing at low to moderate angles of attack tends to reduce the pressure peaks associated with leading-edge vortices and to increase the suction peak around the leading edge, such that the integrated value of the surface pressure remains about the same.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 89-0341
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Computational optimization of a pneumatic forebody flow control concept (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: The effectiveness of a tangential slot blowing concept for generating lateral control forces on an aircraft forebody is analyzed using computational fluid dynamics. The flow about a fighter forebody is computed using a multiple-zone, thin-layer Navier-Stokes code. Tangential slot blowing is modeled by the use of an actuator plane. The effects of slot location and slot length on the efficiency of the system are analyzed. Results of the study indicate that placement of the slot near the nose of the aircraft greatly enhances the efficiency of the system, while the length and circumferential location of the slot are of secondary importance. Efficiency is defined by the amount of side force or yawing moment obtained per unit blowing coefficient. The effect of sideslip on the system is also analyzed. The system is able to generate incremental changes in forces and moments in flows with sideslip angles up to 10 deg comparable to those obtained at zero sideslip. These results are used to determine a baseline configuration for an experimental study of the tangential slot blowing concept.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 91-3249 , AIAA Applied Aerodynamics Conference; Sept. 23-25, 1991; Baltimore, MD; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Transpiration cooling in hypersonic flight (1989)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A preliminary numerical study of transpiration cooling applied to a hypersonic configuration is presented. Air transpiration is applied to the NASA all-body configuration flying at an altitude of 30500 m with a Mach number of 10.3. It was found that the amount of heat disposal by convection is determined primarily by the local geometry of the aircraft for moderate rates of transpiration. This property implies that different areas of the aircraft where transpiration occurs interact weakly with each other. A methodology for quick assessments of the transpiration requirements for a given flight configuration is presented.
    Keywords: AERODYNAMICS
    Type: NASA-CR-186435 , NAS 1.26:186435 , SU-JIAA-TR-92
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    A concurrent hybrid Navier-Stokes/Euler approach to fluid dynamic computations (1993)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: We present a methodology for the numerical simulation of flow fields by the simultaneous application of two distinct approaches to computational aerodynamics. We compute the three dimensional flow field of a missile at moderate angle of attack by dividing the flow field into two regions: a region near the surface where we use a structured grid and a Navier Stokes solver, and a region farther away from the surface where we utilize an unstructured grid and an Euler solver. The two solvers execute as independent UNIX processes either on the same machine or on two machines. The solvers communicate data across their common interfaces within the same machine or over the network. The computations indicate that extensively separated flow fields can be computed without significant distortion by combining viscous and inviscid solvers.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 93-0789 , ; 8 p.|AIAA, Aerospace Sciences Meeting and Exhibit; Jan 11, 1993 - Jan 14, 1993; Reno, NV; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Navier Stokes computation of the flow field over delta wings with spanwise leading edge blowing (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The concept of spanwise leading edge blowing, a means of controlling the position and strength of leading edge vortices, is analyzed by numerical solutions of the three-dimensional Thin-Layer Navier Stokes equations. The leading edge jet is simulated by defining a permeable boundary, corresponding to the jet slot, where suitable boundary conditions are implemented. Numerical results agree favorably with experimental measurements. It is found that the use of spanwise leading edge blowing not only magnifies the size and strength of the leading edge vortices, but also moves the vortex cores outboard and upward. As a result, the increase in lift comes primarily from the greater nonlinear vortex lift. The presence of the leading edge jet stream displaces the flow outboard, thereby increasing the effective aspect ratio of the delta wing. However, blowing causes earlier vortex breakdown, thus decreasing the stall angle.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 88-2558 , AIAA Applied Aerodynamics Conference; Jun 06, 1988 - Jun 08, 1988; Williamsburg, VA; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...