Search Results

open access

Quasi-Cylindrical Theory of Wing-Body Interference at Supersonic Speeds and Comparison with Experiment

Description: "A theoretical method is presented for calculating the flow field about wing-body combinations employing bodies deviating only slightly in shape from a circular cylinder. The method is applied to the calculation of the pressure field acting between a circular cylindrical body and a rectangular wing. The case of zero body angle of attack and variable wing incidence is considered as well as the case of zero wing incidence and variable body angle of attack" (p. 1299).
Date: January 4, 1954
Creator: Nielsen, Jack N.
open access

Review of experimental investigations of liquid-metal heat transfer

Description: Experimental data of various investigators of liquid-metal heat-transfer characteristics were reevaluated using as consistent assumptions and methods as possible and then compared with each other and with theoretical results. The reevaluated data for both local fully developed and average Nusselt numbers in the turbulent flow region were found still to have considerable spread, with the bulk of the data being lower than predicted by existing analysis. An equation based on empirical grounds whic… more
Date: November 4, 1954
Creator: Lubarsky, Bernard & Kaufman, Samuel J.
open access

Formulas for the Elastic Constants of Plates With Integral Waffle-Like Stiffening

Description: "Formulas are derived for the fifteen elastic constants associated with bending, stretching, twisting, and shearing of plates with closely spaced integral ribbing in a variety of configurations and proportions. In the derivation the plates are considered, conceptually, as more uniform orthotropic plates somewhat on the order of plywood. The constants, which include the effectiveness of the ribs for resisting deformations other than bending and stretching in their longitudinal directions, are de… more
Date: 1954
Creator: Dow, Norris F.; Libove, Charles & Hubka, Ralph E.
open access

A Study of the Problem of Designing Airplanes With Satisfactory Inherent Damping of the Dutch Roll Oscillation

Description: "Considerable interest has recently been shown in means of obtaining satisfactory stability of the dutch roll oscillation for modern high-performance airplanes without resort to complicated artificial stabilizing devices. One approach to this problem is to lay out the airplane in the earliest stages of design so that it will have the greatest practicable inherent stability of the lateral oscillation. The present report presents some preliminary results of a theoretical analysis to determine the… more
Date: 1954
Creator: Campbell, John P. & McKinney, Marion O., Jr.
open access

Application of several methods for determining transfer functions and frequency response of aircraft from flight data

Description: In the process of analyzing the longitudinal frequency-response characteristics of aircraft, information on some of the methods of analysis has been obtained by the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics. In the investigation of these methods, the practical applications and limitations were stressed. In general, the methods considered may be classed as: (1) analysis of sinusoidal response, (2) analysis of transient response as to harmonic content thro… more
Date: 1954
Creator: Eggleston, John M. & Mathews, Charles W.
open access

A revised gust-load formula and a re-evaluation of v-g data taken on civil transport airplanes from 1933 to 1950

Description: From Summary: "A revised gust-load formula with a new gust factor is derived to replace the gust-load formula and alleviation factor widely used in gust studies. The revised formula utilizes the same principles and retains the same simple form of the original formula but provides a more appropriate and acceptable basis for gust-load calculations. The gust factor is calculated on the basis of a one-minus-cosine gust shape and is presented as a function of a mass-ratio parameter in contrast to th… more
Date: 1954
Creator: Pratt, Kermit G. & Walker, Walter G.
open access

Shock-turbulence interaction and the generation of noise

Description: Interaction of convected field of turbulence with shock wave is analyzed to yield modified turbulence, entropy spottiness, and noise generated downstream of the shock. Analysis is generalization of single-spectrum-wave treatment of NACA-TN-2864. Formulas for spectra and correlations are obtained. Numerical calculations yield curves of rms velocity components, temperature, pressure, and noise in db against Mach number for m = 1 to infinity; both isotropic and strongly axisymmetric (lateral/longi… more
Date: June 3, 1954
Creator: Ribner, H. S.
open access

On slender-body theory at transonic speeds

Description: The basic ideas of the slender-body approximation have been applied to the nonlinear transonic-flow equation for the velocity potential in order to obtain some of the essential features of slender-body theory at transonic speeds. The results of the investigation are presented from a unified point of view which demonstrates the similarity of slender-body solutions in the various Mach number ranges. The transonic area rule and some conditions concerning its validity follow from the analysis. (aut… more
Date: January 18, 1954
Creator: Harder, Keith C. & Klunker, E. B.
open access

Axial-load fatigue properties of 24S-T and 75S-T aluminum alloy as determined in several laboratories

Description: In the initial phase of a NACA program on fatigue research, axial-load tests on 24S-T3 and 75S-T6 aluminum-alloy sheet have been made at the Battelle Memorial Institute and at the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics. The test specimens were polished and unnotched. The manufacturer of the material, the Aluminum Company of America, has made axial-load tests on 24S-T4 and 75S-T6 rod material. The test techniques used at the three laboratories are desc… more
Date: 1954
Creator: Grover, H. J.; Hyler, W. S.; Kuhn, Paul; Landers, Charles B. & Howell, F. M.
open access

Theoretical performance characteristics of sharp-lip inlets at subsonic speeds

Description: A method is presented for the estimation of the subsonic-flight-speed characteristics of sharp-lip inlets applicable to supersonic aircraft. The analysis, based on a simple momentum balance consideration, permits the computation of inlet-pressure-recovery mass-flow relations and additive-drag coefficients for forward velocities from zero to the speed of sound. The penalties for operation of a sharp-lip inlet at velocity ratios other than 1.0 may be severe; at lower velocity ratios an additive d… more
Date: 1954
Creator: Fradenburgh, Evan A. & Wyatt, DeMarquis D.
open access

On the Use of the Indicial-Function Concept in the Analysis of Unsteady Motions of Wings and Wing-Tail Combinations

Description: "The concept of indicial aerodynamic functions is applied to the analysis of the short-period pitching mode of aircraft. By the use of simple physical relationships associated with the indicial-function relationships concept, quantitative studies are made of the separate effects on the damping in pitch of changes in Mach number, aspect ratio, plan-form shape, and frequency. The concept is further shown to be of value in depicting physically the induced effects on a tail surface which follows in… more
Date: 1954
Creator: Tobak, Murray
open access

Matrix methods for determining the longitudinal-stability derivatives of an airplane from transient flight data

Description: Three matrice methods are developed and presented for determining the longitudinal-stability derivatives from transient flight data. In these methods the expressions for some of the stability derivatives are in the form generally used in stability calculations. The first method requires the combination of four measurements in time-history form, two of which must be incremental elevator deflection and incremental tail load and the other two measurements can be chosen from a possible three, namel… more
Date: 1954
Creator: Donegan, James J.
open access

Exact solutions of laminar-boundary-layer equations with constant property values for porous wall with variable temperature

Description: From Summary: "Exact solution of the laminar-boundary-layer equations for wedge-type flow with constant property values are presented for transpiration-cooled surfaces with variable wall temperatures. The difference between wall and stream temperature is assumed proportional to a power of the distance from the leading edge. Solutions are given for a Prandtl number of 0.7 and ranges of pressure-gradient, cooling-air-flow, and wall-temperature-gradient parameters. Boundary-layer profiles, dimensi… more
Date: July 15, 1954
Creator: Donoughe, Patrick L. & Livingood, John N. B.
open access

Generalized Indical Forces on Deforming Rectangular Wings in Supersonic Flight

Description: "A method is presented for determining the time-dependent flow over a rectangular wing moving with a supersonic forward speed and undergoing small vertical distortions expressible as polynomials involving spanwise and chordwise distances. The solution for the velocity potential is presented in a form analogous to that for steady supersonic flow having the familiar "reflected area" concept discovered by Evvard. Particular attention is paid to indicial-type motions and results are expressed in te… more
Date: June 30, 1954
Creator: Lomax, Harvard; Fuller, Franklyn B. & Sluder, Loma
open access

Analysis of Turbulent Heat Transfer, Mass Transfer, and Friction in Smooth Tubes at High Prandtl and Schmidt Numbers

Description: From Introduction: "In the analysis given herein, which was made at the NACA Lewis laboratory, the expression for eddy diffusivity given in reference 1 is modified in order to account for the effect of kinematic viscosity in reducing the turbulence in the region close to the wall. The effects of variable viscosity and of length-to-diameter ratio are also investigated."
Date: February 17, 1954
Creator: Deissler, Robert G.
open access

Minimum-drag ducted and pointed bodies of revolution based on linearized supersonic theory

Description: The linearized drag integral for bodies of revolution at supersonic speeds is presented in a double-integral form which is not based on slender-body approximations but which reduces to the equal slender-body expression in the proper limit. With the aid of a suitably chosen auxiliary condition, the minimum-external-wave-drag problem is solved for a transition section connecting two semi-infinite cylinders. The projectile tip is a special case and is compared with the Von Karman projectile tip. C… more
Date: March 1, 1954
Creator: Parker, Hermon M.
open access

Effect of ground interference on the aerodynamic and flow characteristics of a 42 degree sweptback wing at Reynolds numbers up to 6.8 x 10(6)

Description: Report presents the results of an investigation of the effects of ground interference on the aerodynamic characteristics of a 42 degree sweptback wing at distances 0.68 and 0.92 of the mean aerodynamic chord from the simulated ground to the 0.25-chord point of the mean aerodynamic chord. Survey data behind the wing, both with and without the simulated ground, are presented in the form of contour charts of downwash, sidewash, and dynamic-pressure ratio at longitudinal stations of 2.0 and 2.8 mea… more
Date: December 17, 1954
Creator: Furlong, G. Chester & Bollech, Thomas V.
open access

Comparison of performance of experimental and conventional cage designs and materials for 75-millimeter-bore cylindrical roller bearings at high speed

Description: From Summary: "The results of two investigations, one to determine the relative merits of four experimental and two conventional design 75-millimeter-bore (size 215) cylindrical roller bearings and one to determine the relative merits of nodular iron and bronze as cage materials for this size and type of bearing, are presented in this report. Nine test bearings were operated over a range of dn values (product of bearing bore in mm and shaft speed in r.p.m) from 0.3 x 10(6) to 2.3 x 20(6), radia… more
Date: June 30, 1954
Creator: Anderson, William J.; Macks, E. Fred & Nemeth, Zolton N.
open access

Similar Solutions for the Compressible Laminar Boundary Layer with Heat Transfer and Pressure Gradient

Description: "Stewartson's transformation is applied to the laminar compressible boundary-layer equations and the requirement of similarity is introduced, resulting in a set of ordinary nonlinear differential equations previously quoted by Stewartson, but unsolved. The requirements of the system are Prandtl number of 1.0, linear viscosity-temperature relation across the boundary layer, an isothermal surface, and the particular distributions of free-stream velocity consistent with similar solutions. This sys… more
Date: October 15, 1954
Creator: Cohen, Clarence B. & Reshotko, Eli
open access

The hydrodynamic characteristics of modified rectangular flat plates having aspect ratios of 1.00, 0.25, and 0.125 and operating near a free water surface

Description: Report presents the results of an investigation conducted to determine the hydrodynamic forces and moments acting on modified rectangular flat plates with aspect ratios of 1.00, 0.25, and 0.125 mounted on a single strut and operating at several depths of submersion. A simple method has been developed by modification of Falkner's vortex-lattice theory which enables the prediction of the lift characteristics in unseparated flow at large depths. This method shows good agreement with experimental d… more
Date: January 19, 1954
Creator: Wadlin, Kenneth L.; Ramsen, John A. & Vaughan, Victor L., Jr.
open access

Axially Symmetric Shapes With Minimum Wave Drag

Description: "The external wave drag of bodies of revolution moving at supersonic speeds can be expressed either in terms of the geometry of the body, or in terms of the body-simulating axial source distribution. For purposes of deriving optimum bodies under various given conditions, it is found that the second of the methods mentioned is the more tractable. By use of a quasi-cylindrical theory, that is, the boundary conditions are applied on the surface of a cylinder rather than on the body itself, the var… more
Date: November 22, 1954
Creator: Heaslet, Max A. & Fuller, Franklyn B.
open access

A wind-tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds

Description: "A method is described for measuring the dynamic stability derivatives of a model airplane in a wind tunnel. The characteristic features of this system are that single-degree-of-freedom oscillations were used to obtain combinations of rolling, yawing and pitching motions; that the oscillations were excited and controlled by velocity feedback which permitted operation under conditions unfavorable for more conventional types of oscillatory testing; and that data processing was greatly simplified … more
Date: September 20, 1954
Creator: Beam, Benjamin H.
open access

The near noise field of static jets and some model studies of devices for noise reduction

Description: An experimental study is presented of the pressure fluctuations near jet exhaust streams made during unchoked operation of a turbojet engine and a 1-inch-diameter high-temperature model jet and during choked operation of various sizes of model jets with unheated air. The tests for unchoked operation indicate a random spectrum of rather narrow band width which varies in frequency content with axial position along the jet. Pressure surveys from the model tests along lines parallel to the 15 degre… more
Date: February 19, 1954
Creator: Lassiter, Leslie W. & Hubbard, Harvey H.
open access

A Thermal Equation for Flame Quenching

Description: "An approximate thermal equation was derived for quenching distance based on a previously proposed diffusional treatment. The quenching distance was expressed in terms of the thermal conductivity, the fuel mole fraction, the heat capacity, the rate of the rate-controlling chemical reaction, a constant that depends on the geometry of the quenching surface, and one empirical constant. The effect of pressure on quenching distance was shown to be inversely proportional to the pressure dependence of… more
Date: December 6, 1954
Creator: Potter, A. E., Jr. & Berlad, A. L.
Back to Top of Screen