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  • 1
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    The kinetic energy of a body of revolution moving in an infinite fluid (1936)
    In:  CASI
    Details
    Publication Date: 2006-10-26
    Keywords: unknown
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  • 2
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    Methods employed in america for the experimental investigation of aerodynamic phenomena at high speeds (1935)
    In:  CASI
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    Publication Date: 2006-10-26
    Keywords: unknown
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  • 3
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    Determination of Venus winds by ground-based radio tracking of the VEGA balloons (1938)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: A global array of 20 radio observatories was used to measure the three-dimensional position and velocity of the two meteorological balloons that were injected into the equatorial region of the Venus atmosphere near Venus midnight by the VEGA spacecraft on June 11 and 15, 1985. Initial analysis of only radial velocities indicates that each balloon was blown westward about 11,500 kilometers (8,000 kilometers on the night side) by zonal winds with a mean speed of about 70 meters per second. Excursions of the data from a model of constant zonal velocity were generally less than 3 meters per second; however, a much larger variation was evident near the end of the flight of the second balloon. Consistent systematic trends in the residuals for both balloons indicate the possibility of a solar-fixed atmospheric feature. Rapid variations in balloon velocity were often detected within a single transmission (330 seconds); however, they may represent not only atmospheric motions but also self-induced aerodynamic motions of the balloon.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science (ISSN 0036-8075); 231; 1414-141
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  • 4
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    Direct broadcasting satellite for educational television - ETV (1935)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Keywords: GENERAL
    Type: NASA, Washington Digest of the Proc. of the Colloq. on Satellite Broadcasting; p 17-20
    Format: text
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  • 5
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    Bibliography of Aeronautics: 1932 (1935)
    In:  CASI
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    Publication Date: 2018-06-05
    Description: This Bibliography of Aeronautics for 1932 covers the aeronautical literature published from January 1 to December 31, 1932. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1931. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is in dictionary form with author and subject entry and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross-reference for research in special lines.
    Keywords: Aeronautics (General)
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  • 6
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    Two-dimensional subsonic compressible flow past elliptic cylinders (1938)
    In:  CASI
    Details
    Publication Date: 2019-05-31
    Keywords: unknown
    Type: REPT.-624
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  • 7
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    The importance of auto-ignition lag in knocking (1935)
    In:  CASI
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    Publication Date: 2019-06-28
    Type: NACA-TN-452
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  • 8
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    Wind tunnel standardization disk drag (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Type: NACA-TN-253
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  • 9
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    Influence of fuel-oil temperature on the combustion in a prechamber compression-ignition engine (1936)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Type: NACA-TN-565
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  • 10
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    Calculations of the Effect of Wing Twist on the Air Forces Acting on a Monoplane Wing (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A method is presented for calculating the aerodynamic forces on a moncylane wing, taking into account the elastic twisting of the wing due to these forces. The lift distribution along the span is calculated by the formulas of Amstutz as a function of the geometrical characteristics of the wing and of the twist at stations 60 and 90 percent of the semispan. The twist for a given lift distribution is calculated by means of influence lines. As a numerical example, the forces on a Swiss military D.2V airplane are calculated. Comparisons with the strip method and with the ordinary stress-analysis method are also given.
    Type: NACA-TN-520
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  • 11
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    Wind-tunnel Tests of a Wing with a Trailing-edge Auxiliary Airfoil Used as a Flap (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report gives the characteristics of a wing with an auxiliary airfoil mounted near its trailing edge and used as a flap. The tests were made with a 10 by 60 inch Clark Y main airfoil and an NACA 0012 flap having a chord equal to 15 percent of the main wing chord. The axis of the flap in all cases was on the flap chord and 20 percent back from its leading edge. The optimum location of the flap axis relative to the main wing for maximum lift was found to be 1.25 percent of the main wing chord behind the trailing edge and 2.5 percent below the chord. In this position C(sub L max) was increased from 1.250 (for the plain wing) to 1.810 at 45 degrees deflection of the flap and C(sub D min) was decreased form 0.0155 to 0.0146 at minus 5 degrees deflection, the coefficient in each case being based on the sum of the flap and wing areas. No serious adverse change in lateral stability was found to result from the use of the flap in the optimum position.
    Type: NACA-TN-524
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  • 12
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    Some Investigations of the General Instability of Stiffened Metal Cylinders V : Stiffened Metal Cylinders Subjected to Pure Bending (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report summarizes the work that has been carried on in the experimental investigation of the problem of general instability of stiffened metal cylinders subjected to pure bending at the C.I.T. This part of the investigation included tests of 46 sheet-covered specimens. The most significant result was the determination of a new design parameter for the case of a stiffened metal cylinder subjected to pure bending.
    Type: NACA-TN-909
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  • 13
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    Tests in the Gust Tunnel of a Model of the XBM-1 Airplane (1939)
    In:  CASI
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    Publication Date: 2019-06-28
    Type: NACA-TN-731
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  • 14
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    An Instrument for Estimating Tautness of Doped Fabrics on Aircraft (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Type: NACA-TN-729
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  • 15
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    The heat transfer of cooling fins on moving air (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The present report is a comparison of the experimentally defined temperature and heat output of cooling fins in the air stream with theory. The agreement is close on the basis of a mean coefficient of heat transfer with respect to the total surface. A relationship is established between the mean coefficient of heat transfer, the dimensions of the fin arrangement, and the air velocity.
    Type: NACA-TM-763
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  • 16
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    Effect of Aerodynamic Design on Glider Performance (1935)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The performance of a glider is determined by means of the velocity polar, which represents the connection between horizontal and sinking speed. The mean sinking speed for a given speed range can be determined on the basis of the velocity polar. These data form the basis for the most propitious design of a performance-type glider with a view to long-distance flight.
    Type: NACA-TM-762
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  • 17
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    Reduction of lift of a wing due to its drag (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This analysis computes for a predetermined airfoil and given Reynolds Number the course of the "displacement thickness," i.e., the course of the layer by which the streamlines of the potential flow are pushed away from the wing through the frictional layer. The result is, to a certain extent, a new wing contour.
    Type: NACA-TM-781
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  • 18
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    Turbulent Jet Expansion (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: This report was made to study the velocity distribution in an open, in a partially open, and in a partially expanding jet. The open-jet observations reveal minor systematic discrepancies from Tollmien's theoretical velocity distribution. The shearing-stress distribution for the partially open jet was determined. The value derived for the ratio of mixing distance to jet width was found to be in close agreement with the corresponding value for the open-jet boundary. The streamline pattern in a partially expanding channel was obtained from the observed velocity distribution and plotted, after which the distribution of the mixing distance for this case was also ascertained.
    Type: NACA-TM-789
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  • 19
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    The formation of ice on airplanes (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The present report examines the problem of ice formation from the point of view of the pilot and the meteorologist. Their experiences prove the ice deposit to be first and foremost a navigational problem and only secondarily a question of de-icing devices. With correct utilization of the meteorological information by the flyer, ice hazard can in many cases be minimized or avoided. Ice formation and the different types of ice deposits are listed and discussed. Weather formation during these ice deposits are also discussed as well as the effect of ice formation on aircraft.
    Type: NACA-TM-786
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  • 20
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    Ignition and Flame Development in the Case of Diesel Fuel Injection (1936)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: To investigate the process of ignition and combustion in the case of spray injection into heated air, a new form of apparatus is developed and the tests carried out with it described. Photographs of the spray before and after ignition are obtained at frequencies of 500 pictures per second. Pressures and temperatures are simultaneously recorded on oscillograms. Information on the initial conditions, ignition time lag, period of complete combustion, place where ignition starts, and general course of the combustion is obtained.
    Type: NACA-TM-790
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  • 21
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    Chief Characteristics and Advantages of Tailless Airplanes (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: This study will be concerned with the critical examination of two main questions, mainly, susceptibility of centering and more generally, the conditions of static stability, longitudinal equilibrium, and the question of dynamic stability, or at least the damping of longitudinal vibrations about a position of equilibrium that may result from a small variation in the angle of attack.
    Type: NACA-TM-794
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  • 22
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    Flow phenomena on plates and airfoils of short span (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: Investigations on the flow phenomena at plates and cambered models were carried out with the aid of force measurements, some pressure distribution measurements, and photographic observation. The experimental methods are described and the results given. Section III of this work gives a comprehensive account of the results and enables us to see how nearly the lift line and lift surface theories agree with the experimental results.
    Type: NACA-TM-798
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  • 23
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    Calculation of the induced efficiency of heavily loaded propellers having infinite number of blades (1939)
    In:  CASI
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    Publication Date: 2019-06-28
    Type: NACA-TM-884
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  • 24
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    High-speed Wind Tunnels (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: Wind tunnel construction and design is discussed especially in relation to subsonic and supersonic speeds. Reynolds Numbers and the theory of compressible flows are also taken into consideration in designing new tunnels.
    Type: NACA-TM-808 , Volta Congress (5th : 1935 : Rome, Italy)
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  • 25
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    Experimental apparatus for the study of propellers (1937)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The apparatus consists of a universal balance with transmission at variable speeds from 300 to 5,000 rpm and a group directly coupled to the model for speeds of 5 to 30,000 revolutions. This new apparatus was also designed with a torsion meter for measuring the torque. Tests were conducted on the effect of the angle between the propeller axis and the wind direction. The results presented correspond to a first series of tests made without an interposed wing and in which the distance between the plane of the propeller disk and the tail was maintained constant.
    Type: NACA-TM-819
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  • 26
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    Experimental Investigation of the Problem of Surface Roughness (1937)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: Based on the universal laws of turbulent velocity distribution at rough and smooth walls, there is in the present work presented a method that allows surface roughness tests and in particular, measurements on the roughness of ship surfaces to be carried out in a much simpler manner. The types of roughness investigated were in the form of flat, rough plates installed in a square-section rectangular channel, the other three walls always being smooth. Twenty-one plates of various roughness were investigated, the roughness elements being the following: spheres of diameter 0.41 and 0.21, respectively, spherical segments, cones, and "short" and "long" angles.
    Type: NACA-TM-823
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  • 27
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    Helicopter problems (1937)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.
    Type: NACA-TM-827
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  • 28
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    Contributions to the theory of incomplete tension bay (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The present report offers an approximate theory for the stress and deformation condition after buckling of the skin in reinforced panels and shells loaded in simple shear and compression and under combined stresses. The theory presents a unified scheme for stresses of these types. It is based upon the concept of a nonuniform stress distribution in the metal panel and its marked power of resistance against compressive stresses ("incomplete" tension bay).
    Type: NACA-TM-831
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  • 29
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    The transport of vorticity through fluids in turbulent motion : in the light of the Prandtl and Taylor theories (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The report studies the problem of the transport of vorticity or of momentum in light of the Taylor and Prandtl theories which are briefly reviewed. It also show how the formulas of Prandtl could be brought into agreement with experimental results in those cases where they agree with the principle of statistic similitude of Karman, and particularly in the problem of the distribution of velocity and temperature in the wake of a heated cylindrical obstacle.
    Type: NACA-TM-799
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  • 30
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    Charts for checking the stability of compression members in trusses (1936)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The present report contains a set of charts developed for computing the fixity effect on a compression member in a truss through its adjacent members, the amount of fixity being considered variable with the particular total truss load. The use of the charts is illustrated on two- and three-bay systems, as well as on a triangular truss.
    Type: NACA-TM-800
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  • 31
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    The Strength of Shell Bodies : Theory and Practice (1937)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: The monocoque form of airplane construction has introduced a number of new problems to the stress calculator and the designer. The problems for the stress calculator fall into two groups: the determination of the stress condition (shell statics) and the determination of the failing strength (shell strength). The present report summarizes the most important theoretical and experimental results on this subject.
    Type: NACA-TM-838
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  • 32
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    Detonation and Autoignition : Some Considerations on Methods of Determination (1937)
    In:  CASI
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    Publication Date: 2019-06-28
    Description: This paper is a critical analysis of the methods of determination of the tendency to detonation. No attempt has been made to describe in detail the different fuels and the different methods proposed.
    Type: NACA-TM-843
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  • 33
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    Stresses in reinforcing rings due to axial forces in cylindrical and conical stressed skins (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: At the ends of a monocoque fuselage concentrated axial forces in the skin must generally be taken up. Such axial forces must also be taken up in the case of other members where axial forces from the neighboring stressed skin construction must be considered. In order to take up these axial forces two bulkheads or reinforcing frames may be arranged at the positions where the forces are applied. If these bulkheads are in the form of rings, bending moments are set up in them. In the present paper computations are performed for obtaining the value of these bending moments.
    Type: NACA-TM-847
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  • 34
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    Comparison of theory with experiment in the phenomenon of wing flutter (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Direct measurements were undertaken at the Aeronautics Laboratory in Turin of the aerodynamic actions on an oscillating wing. The tests conducted had as their essential object the examination of the operation of apparatus designed for this measurement. The values experimentally obtained for the aerodynamic coefficients are in good agreement with the theory of oscillatory motion of the wing of finite span and show clear deviation from the values obtained by theory of plane motion.
    Type: NACA-TM-887
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  • 35
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    Investigation of the lift distribution over the separate wings of a biplane (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An investigation is made of the mutual interference of the wings of a biplane under the general assumption that each wing may be replaced by a vortex system of the type given by the Prandtl wing theory. The additional velocities induced at each wing by the presence of the other are determined by the Biot-Savart law and converted into an equivalent change in the angle of attack, the effect being that of an additional twist given to the wings in changing their lift distributions. The lift distributions computed in this manner for several airplane types are compared with the results of measurement.
    Type: NACA-TM-889
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  • 36
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    The Way to Increased Airplane Engine Power (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The purpose of this paper is to give an outline of the present state of development and point out the possibilities available for the further increase in the power/displacement ratio, the economy, and the reliability of the engine. Some of the aspects discussed are methods of increasing take-off power, the various methods of preparation of the fuel mixture and their effect on power, economy, and safety.
    Type: NACA-TM-894
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  • 37
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    The limit of stability of a curved plate strip under shear and axial stresses (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: For an infinitely long plate strip of constant curvature there is set up the buckling condition for combined shear and axial stresses. Assumptions are made of the vanishing of the moments acting on the longitudinal edges and of the vanishing of the tangential displacements u and the transverse stresses sigma(sub y) (longitudinal stiffeners nonresistant to bending in the circumferential direction). The buckling condition is evaluated for the case of pure shear and an approximate formula is derived for the critical stresses for large curvatures. In connection with the discussion of the methods and results there is defined the range of validity and the buckling condition set up.
    Type: NACA-TM-898
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  • 38
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    Design of centrifugal impeller blades (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This paper restricts itself to radial impellers with cylindrical blades since, as Prasil has shown, the flow about an arbitrarily curved surface of revolution may be reduced to this normal form we have chosen by a relatively simple conformal transformation. This method starts from the simple hypotheses of the older centrifugal impeller theory by first assuming an impeller with an infinite number of blades. How the flow is then modified is then investigated. For the computation of flow for a finite number of blades, the approximation method as developed by Munk, Prandtl and Birnbaum, or Glauert is found suitable. The essential idea of this method is to replace the wing by a vortex sheet and compute the flow as the field of these vortices. The shape of the blades is then obtained from the condition that the flow must be along the surface of the blade.
    Type: NACA-TM-902
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  • 39
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    Effect of transition in cross-sectional shape on the development of the velocity and pressure distribution of turbulent flow in pipes (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: With regard to the change in shape of the cross section while the area remains constant, no investigation results are as yet available. Such an investigation will be the subject of the present paper. For this purpose it is necessary to consider the velocity and pressure relations over each entire cross section so that we are confronted with a three-dimensional problem.
    Type: NACA-TM-903
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  • 40
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    The Enlarged N.A.C.A. Tank, and Some of Its Work (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The most conspicuous of the features of the enlarged N.A.C.A. tank are derived directly from those of the original tank and owe their present form not only to the reasons for their first use but also to the experience obtained with them. As in the original tank, there are: 1) A basin of great length (new 2,880 feet); 2) Rails made of structural H beams, without machining; 3) A towing carriage of very high speed (now 80 mph maximum); 4) Rubber tires on all the wheels, pneumatic on the running wheels and solid on the guide wheels.
    Type: NACA-TM-918
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  • 41
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    Load Tests on a Stiffened Circular Cylindrical Shell (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The present report describes tests in which the stress distribution may be determined in a stiffened circular cylindrical shell loaded longitudinally at four symmetrically situated points. As being of particular importance are the cases investigated of groups of bending and arching or convexing forces, respectively. From the stress measurements on the longitudinal stiffeners, the shear stresses and the bulkhead ring stresses in the skin could be evaluated. These measurements showed that the "simple shear field" used in theoretical computations in which all normal stresses in the skin are neglected, must be extended by the addition of the transverse or circumferential stresses if the bulkhead rings are not riveted to the skin.
    Type: NACA-TM-864
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  • 42
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    Behavior of Static Pressure Heads at High Speeds (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: These tests proved the practicability of static pressure heads at speeds up to 400 km/h (248.5 mph). It weighs 6.5 kg or 2.5 times as much as the old head. The position of the pressure head below the airplane was determined by bearing method at different speeds and for different lengths of suspension. It was established that for the measured speed range a 20 to 24 meter suspension length was sufficient to assure a minimum distance of 6 meters from the airplane without introducing any appreciable errors in the results due to wrong static pressure.
    Type: NACA-TM-865
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  • 43
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    Ice Formation on Wings (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report makes use of the results obtained in the Gottingen ice tunnel in which the atmospheric conditions are simulated and the process of ice formation photographed. The effect of ice formation is threefold: 1) added weight to the airplane; 2) a change in the lift and drag forces; 3) a change in the stability characteristics.
    Type: NACA-TM-888 , Lilienthal-Gesellschaft fur Luftfahrtforschung ( 1938 : Berlin)
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  • 44
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    The Power of Aircraft Engines at Altitude (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The subject of the present paper is confined to the investigations and methods employed by the Fiat company in their studies on the altitude performance of an air-cooled engine of the production type. The experimental set-up as well as test engine data are provided.
    Type: NACA-TM-895 , Lilienthal-Gesellschaft fur Luftfahrtforschung ( 1938 : Berlin)
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  • 45
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    The hydrodynamic theory of detonation (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report derives equations containing only directly measurable constants for the quantities involved in the hydrodynamic theory of detonation. The stable detonation speed, D, is revealed as having the lowest possible value in the case of positive material velocity, by finding the minimum of the Du curve (u denotes the speed of the gases of combustion). A study of the conditions of energy and impulse in freely suspended detonating systems leads to the disclosure of a rarefaction front traveling at a lower speed behind the detonation front; its velocity is computed. The latent energy of the explosive passes into the steadily growing detonation zone - the region between the detonation front and the rarefaction front. The conclusions lead to a new definition of the concept of shattering power. The calculations are based on the behavior of trinitrotoluene.
    Type: NACA-TM-899
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  • 46
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    Stability of rectangular plates with longitudinal or transverse stiffeners under uniform compression (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: In the present paper, the complete buckling conditions of stiffened plates are being developed for uniform compression. We shall treat plates with one or two longitudinal or transverse stiffeners at any point, discuss the buckling conditions, and evaluate them for different cases.
    Type: NACA-TM-904
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  • 47
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    Two-stroke-cycle engines with unsymmetrical control diagram : supercharged engines (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: As no investigation of supercharging in 2-stroke-cycle engines has been published up to the present, this article is an attempt in that direction, with a view to establishing the mathematical principles and the constructive rules for the design of such engines.
    Type: NACA-TM-908
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  • 48
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    Measurement of the True Dynamic and Static Pressures in Flight (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: In this report, two reliable methods are presented, with the aid of which the undisturbed flight dynamic pressure and the true static pressure may be determined without error. These problems were solved chiefly through practical flight tests.
    Type: NACA-TM-913
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  • 49
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    Wind-tunnel Investigations on Flexural-torsional Wing Flutter (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: For the purpose of testing the theory of an oscillating airfoil of two degrees of freedom, a wing was mounted in the wind tunnel between two walls in such a manner that it could execute vertical (flexural) oscillations as well as torsional oscillations about an arbitrary axis parallel to the span. It was possible to vary the inertia and elasticity parameters and also to increase artificially the negligibly small natural damping of the system. The oscillations were recorded to a strongly magnified scale. The experimentally determined critical (or flutter) velocities fully agree with the theoretical ones of Wagner and Kussner within the limits of computational and measuring accuracy. An extremely narrow wing without end walls (three dimensional problem) showed the same oscillations as one with end walls (two-dimensional problem).
    Type: NACA-TM-877
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  • 50
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    Theory of two-dimensional potential flow about arbitrary wing sections (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Three general theories treating the potential flow about an arbitrary wing section are discussed in this report. The first theory treats the method of conformal transformation as laid down by Theodorsen and Garrick; the second is a generalization of Birnbaum's theory for moderately thick airfoils; the third is a general investigation of the complex velocity function with particular reference to the relations first discussed by F. Weinig.
    Type: NACA-TM-886
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  • 51
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    Experiments on a Slotted Wing (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The results of pressure distribution measurements that were made on a model wing section of a Fieseler F 5 R type airplane are presented. Comparison of those model tests with the corresponding flight tests indicates the limitations and also the advantages of wind tunnel investigations, the advantages being particularly that through the variety of measuring methods employed the more complicated flow conditions may also be clarified. A fact brought out in these tests is that even in the case of "well rounded" slots it is possible for a vortex to be set up at the slot entrance and this vortex is responsible for certain irregularities in the pressure distribution and in the efficiency of the slot.
    Type: NACA-TM-890
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  • 52
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    Contribution to the theory of the heated duct radiator (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A method is developed with no neglect of certain factors in mass flow of air and in the drag of the heated radiator, i.e., one under actual operating conditions, as compared with the corresponding values in the cold state, may be simply computed. Although a symmetrical duct radiator has been used to bring out the flow relations, the results apply equally as well to the unsymmetrical radiator shapes usual in airplane construction.
    Type: NACA-TM-893
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  • 53
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    Airfoil Theory at Supersonic Speed (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A theory is developed for the airfoil of finite span at supersonic speed analogous to the Prandtl airfoil theory of 1918-1919 for incompressible flow. In addition to the profile and induced drags, account must be taken at supersonic flow of still another drag, namely, the wave drag, which is independent of the wing aspect ratio. Both wave and induced drags are proportional to the square of the lift and depend on the Mach number, that is, the ratio of flight to sound speed. In general, in the case of supersonic flow, the drag-lift ratio is considerably less favorable than is the case for incompressible flow. Among others the following examples are considered: 1) lifting line with constant lift distribution (horseshoe vortex); 2) computation of wave and induced drag and the twist of a trapezoidal wing of constant lift density; 3) computation of the lift distribution and drag of an untwisted rectangular wing.
    Type: NACA-TM-897
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  • 54
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    The effect of the masses of the controls on the longitudinal stability with free elevator. Part I (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: In the present report, aerodynamic relations under the effect of the weight moments are investigated, and an example given of the computation of the stability for a practical case. Later, the effects of the masses of the controls on the dynamic longitudinal stability will be considered.
    Type: NACA-TM-900
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  • 55
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    Temperature-indicating Paints (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report is an attempt at a new method of coating the surface of the cylinder with materials that undergo chemical change at definite temperatures as indicated by a change in color. In this way it was hoped that the substance itself would indicate directly the position of its isotherms, which in measurements with thermocouples requires a tedious amount of labor.
    Type: NACA-TM-905
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  • 56
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    Aerodynamic Characteristics of a 4-engine Monoplane Showing Effects of Enclosing the Engines in the Wing and Comparisons of Tractor- and Pusher-propeller Arrangements (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Type: NACA-WR-L-456
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  • 57
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    Ground-cooling and Flight Tests of an Airplane Equipped with a Nose-blower Engine Cowling (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Type: NACA-WR-L-478
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  • 58
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    Preliminary report on the characteristics of the NACA 4400R series airfoils (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Type: NACA-WR-L-451
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  • 59
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    Preliminary Report on Laminar-Flow Airfoils and New Methods Adopted for Airfoil and Boundary-Layer Investigations (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Recent developments in airfoil-testing methods and fundamental air-flow investigations, as applied to airfoils, are discussed. Preliminary test results, obtained under conditions relatively free from stream turbulence and other disturbances, are presented. Suitable airfoils and airfoil-design principles were developed to take advantage of the unusually extensive laminar boundary layers that may be maintained under the improved testing conditions. The results are of interest mainly in range of below 6,000,000.
    Keywords: Aerodynamics
    Type: NACA-WR-L-345
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  • 60
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    Acceleration, Stress, and Deflection Measurements on the XB-15 Bomber in Gusty Air (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Type: NACA-WR-L-540
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  • 61
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    The Effect of Nacelle-Propeller Diameter Ratio on Body Interference and on Propeller and Cooling Characteristics (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of an investigation conducted in the NACA 20-foot tunnel to determine the slipstream drag, the body interference, and the cooling characteristics of nacelle-propeller diameter. Four combinations of geometrically similar propellers and nacelles, mounted on standard wing supports, were tested with values of the ratio of nacelle diameter to propeller diameter of 0.25, 0.33, and 0.44.
    Type: NACA-TR-680
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  • 62
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    Surface heat-transfer coefficients of finned cylinders (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An investigation to determine and correlate the experimental surface heat-transfer coefficients of finned cylinders with different air-stream cooling arrangements was conducted at the Langley Memorial Aeronautical Laboratory from 1932 to 1938. The investigation covered the determination of the effect of fin width, fin space, fin thickness, and cylinder diameter on the heat transfer. Wind-tunnel tests were made in the free air stream with and without baffles and also with various devices for creating a turbulent air stream. Tests were also made with blower.
    Type: NACA-TR-676
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  • 63
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    Effects of Elevator Nose Shape, Gap, Balance, and Tabs on the Aerodynamic Characteristics of a Horizontal Tail Surface (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Results are presented showing the effects of gap, elevator, nose shape, balance, cut-out, and tabs on the aerodynamic characteristics of a horizontal tail surface tested in the NACA full-scale tunnel.
    Type: NACA-TR-675
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  • 64
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    Determination of the Profile Drag of an Airplane Wing in Flight at High Reynolds Numbers (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Flight tests were made to determine the profile-drag coefficients of a portion of the original wing surface of an all-metal airplane and of a portion of the wing made aerodynamically smooth and more nearly fair than the original section. The wing section was approximately the NACA 2414.5. The tests were carried out over a range of airplane speeds giving a maximum Reynolds number of 15,000,000. Tests were also carried out to locate the point of transition from laminar to turbulent boundary layer and to determine the velocity distribution along the upper surface of the wing. The profile-drag coefficients of the original and of the smooth wing portions at a Reynolds number of 15,000,000 were 0.0102 and 0.0068, respectively; i.e., the surface irregularities on the original wing increased the profile-drag coefficient 50 percent above that of the smooth wing.
    Type: NACA-TR-667
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  • 65
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    Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with the geometry of the combination. An interference burble, which markedly increases the glide-path angle and the stability in pitch before the actual stall, may be considered a means of obtaining satisfactory stalling characteristics for complete combination.
    Type: NACA-TR-678
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  • 66
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    Wind-tunnel investigation of NACA 23012 airfoil with various arrangements of slotted flaps (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An investigation was made in the NACA 7 by 10-foot wind tunnel of a large-chord NACA 23012 airfoil with several arrangements of 25.66 percent chord slotted flaps to determine the section aerodynamic characteristics as affected by slot shape, flap shape, flap location, and flap deflection. The flap position for maximum lift, the polars for arrangements considered favorable for take-off and climb, and the complete section aerodynamic characteristics for selected optimum arrangements were determined. A discussion is given of the relative merits of the various arrangement for certain selected criterions. A comparison is made of a slotted flap on the NACA 23021 airfoil with a corresponding slotted flap previously developed for the NACA 23012 airfoil.
    Type: NACA-TR-677
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  • 67
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    Cooling on the Front of an Air-cooled Engine Cylinder in a Conventional Engine Cowling (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Measurements were made of the cooling on the fronts of model cylinders in a conventional cowling for cooling in both the ground and the cruising conditions. The mechanisms of front and rear cooling are essentially different. Cooling on the rear baffled part of the cylinders continually increases with increasing fin width. For the front of the cylinder, an optimum fin width was found to exist beyond which an increase in width reduced the heat transfer. The heat transfer coefficient on the front of the cylinders was larger on the side of the cylinder facing the propeller swirl than on the opposite side. This effect became more pronounced as the fin width was increased. These results are introductory to the study of front cooling and show the general effect of several test parameters.
    Type: NACA-TR-674
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  • 68
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    Experimental Verification of the Theory of Oscillating Airfoils (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Measurements have been made of the lift on an airfoil in pitching oscillation with a continuous-recording, instantaneous-force balance. The experimental values for the phase difference between the angle of attack and the lift are shown to be in close agreement with theory.
    Type: NACA-TR-673
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  • 69
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    Free-Spinning Wind-Tunnel Tests of a Low-Wing Monoplane with Systematic Changes in Wings and Tails IV : Effect of Center-of-Gravity Location (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Eight wings and three tails, covering a wide range of aerodynamic characteristics, were independently ballasted so as to be interchangeable with no change in mass distribution. For each of the 24 resulting wing-tail combinations, observations were made of the steady spin for four control settings and of recoveries for five control manipulations. The results are presented in the form of charts comparing the spin characteristics. The tests are part of a general investigation being made in the NACA free-spinning tunnel to determine the effects of systematic changes in wing and tail arrangement upon the steady-spin and the recovery characteristics of a conventional low-wing monoplane for various load distributions.
    Type: NACA-TR-672
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  • 70
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    A theoretical study of the moment on a body in a compressible fluid (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The extension to a compressible fluid of Lagally's theorem on the moment on a body in an incompressible fluid and Poggi's method of treating the flow of compressible fluids are employed for the determination of the effect of compressibility on the moment of an arbitrary body. Only the case of the two-dimensional subsonic flow of an ideal compressible fluid is considered. As examples of the application of the general theory, two well-known systems of profiles are treated; namely the elliptic profile and the symmetrical Joukowski profiles with sharp trailing edges. The effect of compressibility on the position of the center of pressure is also discussed. Several numerical examples of both the elliptic and the Joukowski profiles are given.
    Type: NACA-TR-671
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  • 71
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    Calculation of the aerodynamic characteristics of tapered wings with partial-span flaps (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Factors derived from wing theory are presented. By means of these factors, the angle of zero lift, the lift-curve slope, the pitching moment, the aerodynamic-center position, and the induced drag of tapered wings with partial-span flaps may be calculated. The factors are given for wings of aspect ratios 6 and 10 , of taper ratios from 0.25 to 1.00, and with flaps of various length. An example is presented of the method of application of the factors. Fair agreement with experimental results is shown for two wings of different taper ratio having plain flaps of various spacing.
    Type: NACA-TR-665
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  • 72
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    Wind-Tunnel and Flight Tests of Slot-lip Ailerons (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The slot-lip ailerons developed by the NACA consist of a flap-type spoiler with an adjoining continuously open slot. The ailerons were developed in an investigation of the delayed response, or lag, of spoiler-type lateral controls. This report presents the results of tests of these slot-lip ailerons made on wing models in the 7 by 10-foot wind tunnel, on a Fairchild 22 airplane in the full-scale wind tunnel and in flight, and on the Weick W1-A airplane in flight.
    Type: NACA-TR-602
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  • 73
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    Spinning Characteristics of the XN2Y-1 Airplane Obtained from the Spinning Balance and Compared with Results from the Spinning Tunnel and from Flight Tests (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of tests of a 1/10-scale model of the XN2Y-1 airplane tested in the NACA 5-foot vertical wind tunnel in which the six components of forces and moments were measured. The model was tested in 17 attitudes in which the full-scale airplane had been observed to spin, in order to determine the effects of scale, tunnel, and interference. In addition, a series of tests was made to cover the range of angles of attack, angles of sideslip, rates of rotation, and control setting likely to be encountered by a spinning airplane. The data were used to estimate the probable attitudes in steady spins of an airplane in flight and of a model in the free-spinning tunnel. The estimated attitudes of steady spin were compared with attitudes measured in flight and in the spinning tunnel. The results indicate that corrections for certain scale and tunnel effects are necessary to estimate full-scale spinning attitudes from model results.
    Type: NACA-TR-607
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  • 74
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    Effect of Service Stress on Impact Resistance, X-ray Diffraction Patterns, and Microstructure of 25s Aluminum Alloy (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of a great number of tests made to determine the effect of service stresses on the impact resistance, the x-ray diffraction patterns, and the microstructure of 25s aluminum alloy. Many of the specimens were taken from actual propeller blades and others were cut from 13/16-inch rod furnished by the Aluminum Company of America.
    Type: NACA-TR-659
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  • 75
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    General airplane performance (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Equations have been developed for the analysis of the performance of the ideal airplane, leading to an approximate physical interpretation of the performance problem. The basic sea-level airplane parameters have been generalized to altitude parameters and a new parameter has been introduced and physically interpreted. The performance analysis for actual airplanes has been obtained in terms of the equivalent ideal airplane in order that the charts developed for use in practical calculations will for the most part apply to any type of engine-propeller combination and system of control, the only additional material required consisting of the actual engine and propeller curves for propulsion unit. Finally, a more exact method for the calculation of the climb characteristics for the constant-speed controllable propeller is presented in the appendix.
    Type: NACA-TR-654
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  • 76
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    A Study of Air Flow in an Engine Cylinder (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A 4-stroke-cycle test engine was equipped with a glass cylinder and the air movements within it were studied while the engine was being motored. Different types of air flow were produced by using shrouded intake valves in various arrangements and by altering the shape of the intake-air passage in the cylinder head. The air movements were made visible by mixing feathers with the entering air, and high-speed motion pictures were taken of them so that the air currents might be studied in detail and their velocities measured. Motion pictures were also taken of gasoline sprays injected into the cylinder on the intake stroke. The photographs showed that: a wide variety of induced air movements could be created in the cylinder; the movements always persisted throughout the compression stroke; and the only type of movement that persisted until the end of the cycle was rotation about the cylinder axis.
    Type: NACA-TR-653
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  • 77
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    The Pack Method for Compressive Tests of Thin Specimens of Materials Used in Thin-Wall Structures (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The strength of modern lightweight thin-wall structures is generally limited by the strength of the compression members. An adequate design of these members requires a knowledge of the compressive stress-strain graph of the thin-wall material. The "pack" method was developed at the National Bureau of Standards with the support of the National Advisory Committee for Aeronautics to make possible a determination of compressive stress-strain graphs for such material. In the pack test an odd number of specimens are assembled into a relatively stable pack, like a "pack of cards." Additional lateral stability is obtained from lateral supports between the external sheet faces of the pack and outside reactions. The tests seems adequate for many problems in structural research.
    Type: NACA-TR-649
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  • 78
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    Tests of NACA 0009, 0012, and 0018 Airfoils in the Full-Scale Tunnel (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An investigation was conducted in the NACA full-scale wind tunnel to determine the aerodynamic characteristics of the NACA 0009, 0012, and 0018 airfoils, with the ultimate purpose of providing data to be used as a basis for comparison with other wind-tunnel data, mainly in the study of scale and turbulence effects. Three symmetrical 6 by 36-foot rectangular airfoils were used. The Reynolds number range for minimum drag was form 1,800,000 to 7,000,000 and for maximum lift, from 1,700,000 to 4,500,000. The effect of rounded tips was determined for each of the airfoils. Tests were also made of the NACA 0012 airfoil equipped with a 0.20c full-span split flap hinged at 0.80c. Tuft surveys were included to show the progressive breakdown of flow near maximum lift. Momentum surveys were made in conjunction with force measurements at zero lift as an aid in converting force-test data to section coefficients.
    Type: NACA-TR-647
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  • 79
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    The Compressibility Burble and the Effect of Compressibility on Pressures and Forces Acting on a Airfoil (1939)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Simultaneous air-flow photographs and pressure-distribution measurements were made of the NACA 4412 airfoil at high speeds to determine the physical nature of the compressibility burble. The tests were conducted in the NACA 24-inch high-speed wind tunnel. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations in the 5-inch-chord airfoil by means of a multiple-tube manometer. Following the general program, a few measurements of total-pressure loss in the wake of the airfoil at high speeds were made to illustrate the magnitude of the losses involved and the extent of the disturbed region; and, finally, in order to relate this work to earlier force-test data, a force test of a 5-inch-chord NACA 4412 airfoil was made. The results show the general nature of the phenomenon known as the compressibility burble. The source of the increased drag is shown to be a compression shock that occurs on the airfoil as its speed approaches the speed of sound. Finally, it is indicated that considerable experimentation is needed in order to understand the phenomenon completely.
    Type: NACA-TR-646
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  • 80
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    Aerodynamic Characteristics of NACA 23012 and 23021 Airfoils with 20-Percent-chord External-Airfoil Flaps of NACA 23012 Section (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of an investigation of the general aerodynamic characteristics of the NACA 23012 and 23021 airfoils, each equipped with a 0.20c external flap of NACA 23012 section. The tests were made in the NACA 7 by 10-foot and variable-density wind tunnels and covered a range of Reynolds numbers that included values corresponding to those for landing conditions of a wide range of airplanes. Besides a determination of the variation of lift and drag characteristics with position of the flap relative to the main airfoil, complete aerodynamic characteristics of the airfoil-flap combination with a flap hinge axis selected to give small hinge moments were measured in the two tunnels. Some measurements of air loads on the flap itself in the presence of the wing were made in the 7 by 10-foot wind tunnel.
    Type: NACA-TR-573
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  • 81
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    Wing-Nacelle-Propeller Interference for Wings of Various Spans Force and Pressure-Distribution Tests (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of an experimental investigation made in the NACA full-scale wind tunnel to determine the effect of wing span on nacelle-propeller characteristics and, reciprocally, the lateral extent of nacelle and propeller influence on a monoplane wing. The results provide a check on the validity of the previous research on nacelles and propellers with 15-foot-span wings tested in the 20-foot wind tunnel and reported in technical reports 415, 462, 505, 506, and 507.
    Type: NACA-TR-569
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  • 82
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    The effect of lateral controls in producing motion of an airplane as computed from wind-tunnel data (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report presents the results of an analytical study of the lateral controllability of an airplane in which both the static rolling and yawing moments supplied by the controls and the reactions due to the inherent stability of the airplane have been taken into account. The investigation was undertaken partly for the purpose of coordinating the results of a long series of wind-tunnel investigations with phenomena observed in flight tests; for this reason a hypothetical average airplane, embodying the essential characteristics of both wind-tunnel models and the full-size test airplanes, was assumed for the study.
    Type: NACA-TR-570
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  • 83
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    Measurements of Fuel Distribution Within Sprays for Fuel-Injection Engines (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Two methods were used to measure fuel distribution within sprays from several types of fuel-injection nozzles. A small tube inserted through the wall of an air tight chamber into which the sprays were injected could be moved about inside the chamber. When the pressure was raised to obtain air densities of 6 and 14 atmospheres, some air was forced through the tube and the fuel that was carried with it was separated by absorbent cotton and weighed. Cross sections of sprays from plain, pintle, multiple-orifice, impinging-jets, centrifugal, lip, slit, and annular-orifice nozzles were investigated, at distances of 1, 3, 5, and 7 inches from the nozzles.
    Type: NACA-TR-565
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  • 84
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    Ground-Handling Forces on a 1/40-scale Model of the U. S. Airship "Akron." (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report presents the results of full-scale wind tunnel tests conducted to determine the ground-handling forces on a 1/40-scale model of the U. S. Airship "Akron." Ground-handling conditions were simulated by establishing a velocity gradient above a special ground board in the tunnel comparable with that encountered over a landing field. The tests were conducted at Reynolds numbers ranging from 5,000,000 to 19,000,000 at each of six angles of yaw between 0 degree and 180 degrees and at four heights of the model above the ground board. The ground-handling forces vary greatly with the angle of yaw and reach large values at appreciable angles of yaw. Small changes in height, pitch, or roll did not critically affect the forces on the model. In the range of Reynolds numbers tested, no significant variation of the forces with the scale was disclosed.
    Type: NACA-TR-566
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  • 85
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    Calculated and Measured Pressure Distributions over the Midspan Section of the NACA 4412 Airfoil (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Pressures were simultaneously measured in the variable-density tunnel at 54 orifices distributed over the midspan section of 5 by 30 inch rectangular model of the NACA 4412 airfoil at 17 angles of attack ranging from -20 degrees to 30 degrees at a Reynolds number of approximately 3,000,000. Accurate data were thus obtained for studying the deviations of the results of potential-flow theory from measured results. The results of the analysis and a discussion of the experimental technique are presented.
    Type: NACA-TR-563
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  • 86
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    A simplified application of the method of operators to the calculation of disturbed motions of an airplane (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A simplified treatment of the application of Heaviside's operational methods to problems of airplane dynamics is given. Certain graphical methods and logarithmic formulas that lessen the amount of computation involved are explained. The problem representing a gust disturbance or control manipulation is taken up and it is pointed out that in certain cases arbitrary control manipulations may be dealt with as though they imposed specific constraints on the airplane, thus avoiding the necessity of any integration. The application of the calculations described in the text is illustrated by several examples chosen to show the use of the methods and the practicability of the graphical and logarithmic computations described.
    Type: NACA-TR-560
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  • 87
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    Wind-Tunnel Tests of 10-foot-diameter Autogiro Rotors (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of a series of 10-foot-diameter autogiro rotor models tested in the NACA 20-foot wind tunnel. Four of the models differed only in the airfoil sections of the blades, the sections used being the NACA 0012, 0018, 4412, and 4418. Three additional models employing the NACA 0012 section were tested, in which a varying portion of the blade near the hub was replaced by a streamline tube with a chord of about one-fourth the blade chord.
    Type: NACA-TR-552
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  • 88
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    Aircraft compass characteristics (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.
    Type: NACA-TR-551
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  • 89
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    Some effects of argon and helium upon explosions of carbon monoxide and oxygen (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of an investigation conducted to study the effects of the inert gases, argon and helium, upon flame speed and expansion ratio in exploding mixtures of carbon monoxide, oxygen and water.For the particular gas mixtures investigated the results show that: (1) With the possible exception of helium in small amounts the addition of inert gas always produces decreased flame speed and expansion ratio; (2) like volumes of argon and helium have very different effects upon flame speed but practically the same effect upon expansion ratio; and (3) the difference in the effect of these two gases upon speed is independent of the ratio of carbon monoxide to oxygen. A discussion of some possible modes by which inert gases may produce the observed effects is included.
    Type: NACA-TR-553
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  • 90
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    Effect of tip shape and dihedral on lateral-stability characteristics (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report presents the results of wind tunnel tests to determine the effect of wing-tip shape and dihedral on some of the aerodynamic characteristics of Clark Y wings that affect the performance and lateral stability of airplanes. Force tests at several angles of yaw and rotation tests at zero yaw were made. From these tests the rates of change of rolling moment, yawing moment, and cross-wind force coefficients with angle of yaw and the rate of change of rolling moment coefficient with rolling were determined.
    Type: NACA-TR-548
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  • 91
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    Interference of Wing and Fuselage from Tests of 209 Combinations in the NACA Variable-Density Tunnel (1936)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report presents the results of tests of 209 simple wing-fuselage combinations made in the NACA variable-density wind tunnel to provide information regarding the effects of aerodynamic interference between wings and fuselages at a large value of Reynolds number.
    Type: NACA-TR-540
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  • 92
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    Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off (1936)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report presents the results of wind tunnel tests of a wing in combination with each of three sizes of Fowler flap. The purpose of the investigation was to determine the aerodynamic characteristics as affected by flap chord and position, the air loads on the flaps, and the effect of flaps on the downwash.
    Type: NACA-TR-534
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  • 93
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    A study of the torque equilibrium of an autogiro rotor (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Two improvements have been made in the method developed in NACA Reports nos. 487 and 591 for the estimation of the inflow velocity required to overcome a given decelerating torque in an autogiro rotor. At low tip-speed ratios, where the assumptions necessary for the analytical integrations of the earlier papers are valid, the expressions therein derived are greatly simplified by combining and eliminating terms with a view of minimizing the numerical computations required. At high tip-speed ratios, by means of charts based on graphical integrations, errors inherent in the assumptions associated with the analytical method are largely eliminated. The suggested method of estimating the inflow velocity presupposes a knowledge of the decelerating torque acting on the rotor; all available full-scale experimental information on this subject is included.
    Type: NACA-TR-623
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  • 94
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    A discussion of certain problems connected with the design of hulls of flying boats and the use of general test data (1938)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report presents the results of a survey of problems encountered in applying general test data to the design of flying-boat hulls. It is shown how basic design features may be readily determined from special plots of test data. A study of the effect of the size of a flying boat on the probable limits to be covered by the general test data is included and recommendations for special tests and new methods of presenting test data for direct use in design are given.
    Type: NACA-TR-625
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  • 95
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    Annual report of the National Advisory Committee for Aeronautics (21st).administrative report including Technical Report nos. 508 to 541 (1936)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.
    Type: NACA-AR-21
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  • 96
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    Tests of Nacelle-Propeller Combinations in Various Positions with Reference to Wings IV : Thick Wing - Various Radial-Engine Cowlings - Tandem Propellers (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report is the fourth of a series giving the results obtained from wind tunnel tests to determine the interference lift and drag and propulsive efficiency of wing-nacelle-propeller combinations. Previous reports give the results of tests with tractor propellers with various forms of nacelles and engine cowlings. This report gives the results of tests of tandem arrangements of engines and propellers in 11 positions with reference to a thick wing.
    Type: NACA-TR-505
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  • 97
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    Computation of the two-dimensional flow in a laminar boundary layer (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A comparison is made of the boundary-layer flow computed by the approximate method developed by K. Pohlhausen with the exact solutions which have been published for several special cases. A modification of Pohlhausen's method has been developed which extends the range of application at the expense of some decrease in the accuracy of the approximations.
    Type: NACA-TR-497
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  • 98
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    The Physical Effects of Detonation in a Closed Cylindrical Chamber (1935)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Detonation in the internal-combustion engine is studied as a physical process. It is shown that detonation is accompanied by pressure waves within the cylinder charge. Sound theory is applied to the calculation of resonant pressure-wave frequencies. Apparatus is described for direct measurement of pressure-wave frequencies. Frequencies determined from two engines of different cylinder sizes are shown to agree with the values calculated from sound theory. An outline of the theoretically possible modes of vibration in a right circular cylinder with flat ends is included. An appendix by John P. Elting gives a method of calculating pressure in the sound wave following detonation.
    Type: NACA-TR-493
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  • 99
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    Experimental Investigation of Wind-Tunnel Interference on the Downwash Behind an Airfoil (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The interference of the wind-tunnel boundaries on the downwash behind an airfoil has been experimentally investigated and the results have been compared with the available theoretical results for open-throat wind tunnels. As in previous studies, the simplified theoretical treatment that assumes the test section to be an infinite free jet has been shown to be satisfactory at the lifting line. The experimental results, however, show that this assumption may lead to erroneous conclusions regarding the corrections to be applied to the downwash in the region behind the airfoil where the tail surfaces are normally located. The results of a theory based on the more accurate concept of the open-jet wind tunnel as a finite length of free jet provided with a closed exit passage are in good qualitative agreement with the experimental results.
    Type: NACA-TR-609
    Format: application/pdf
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  • 100
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    Stress Analysis of Beams with Shear Deformation of the Flanges (1937)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This report discusses the fundamental action of shear deformation of the flanges on the basis of simplifying assumptions. The theory is developed to the point of giving analytical solutions for simple cases of beams and of skin-stringer panels under axial load. Strain-gage tests on a tension panel and on a beam corresponding to these simple cases are described and the results are compared with analytical results. For wing beams, an approximate method of applying the theory is given. As an alternative, the construction of a mechanical analyzer is advocated.
    Type: NACA-TR-608
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