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

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

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, dimensionless boundary-layer thicknesses, and convective heat-transfer coefficients are given in both tabular and graphical form. Corresponding results for constant wall temperature and for impermeable surfaces are included for comparison purposes."
Date: July 15, 1954
Creator: Donoughe, Patrick L. & Livingood, John N. B.
System: The UNT Digital Library
Generalized Indical Forces on Deforming Rectangular Wings in Supersonic Flight (open access)

Generalized Indical Forces on Deforming Rectangular Wings in Supersonic Flight

"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 terms of generalized indicial forces. Numerical results for Mach numbers equal to 1.1 and 1.2 are given for polynomials of the first and fifth degree in the chordwise and spanwise directions, respectively, on a wing having an aspect ratio of 4" (p. 595).
Date: June 30, 1954
Creator: Lomax, Harvard; Fuller, Franklyn B. & Sluder, Loma
System: The UNT Digital Library
Analysis of Turbulent Heat Transfer, Mass Transfer, and Friction in Smooth Tubes at High Prandtl and Schmidt Numbers (open access)

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

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.
System: The UNT Digital Library
Minimum-drag ducted and pointed bodies of revolution based on linearized supersonic theory (open access)

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

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. Calculations are presented which indicate that the method of analysis gives good first-order results in the moderate supersonic range.
Date: March 1, 1954
Creator: Parker, Hermon M.
System: The UNT Digital Library
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) (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)

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 mean aerodynamic chords behind the wing.
Date: December 17, 1954
Creator: Furlong, G. Chester & Bollech, Thomas V.
System: The UNT Digital Library
Comparison of performance of experimental and conventional cage designs and materials for 75-millimeter-bore cylindrical roller bearings at high speed (open access)

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

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), radial loads for 7 to 1613 pounds, and oil flows from 2 to 8 pounds per minute with a single-jet circulatory oil feed. Of the six bearings used to evaluate designs, four were experimental types with outer-race-riding cages and inner-race-guided rollers, and two were conventional types, one with outer-race-guided rollers and cage and one with inner-race-guided rollers and cage."
Date: June 30, 1954
Creator: Anderson, William J.; Macks, E. Fred & Nemeth, Zolton N.
System: The UNT Digital Library
Similar Solutions for the Compressible Laminar Boundary Layer with Heat Transfer and Pressure Gradient (open access)

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

"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 system admits axial pressure gradients of arbitrary magnitude, heat flux normal to the surface, and arbitrary Mach numbers" (p. 1).
Date: October 15, 1954
Creator: Cohen, Clarence B. & Reshotko, Eli
System: The UNT Digital Library
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 (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

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 data from the present tests and with aerodynamic data at all angles investigated for aspect ratios of 1.00 and 0.25 and at angles up to 16 degrees for aspect ratio 0.125. Above 16 degrees for aspect ratio 0.125, the predicted lift proved too high.
Date: January 19, 1954
Creator: Wadlin, Kenneth L.; Ramsen, John A. & Vaughan, Victor L., Jr.
System: The UNT Digital Library
Axially Symmetric Shapes With Minimum Wave Drag (open access)

Axially Symmetric Shapes With Minimum Wave Drag

"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 variational problems of the optimum bodies having prescribed volume or caliber are solved" (p. 131).
Date: November 22, 1954
Creator: Heaslet, Max A. & Fuller, Franklyn B.
System: The UNT Digital Library
A wind-tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds (open access)

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

"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 by using analog computer elements in the strain-gage circuitry. A small number of experimental data are included to illustrate the general scope of results obtainable with this system" (p. 1).
Date: September 20, 1954
Creator: Beam, Benjamin H.
System: The UNT Digital Library
The near noise field of static jets and some model studies of devices for noise reduction (open access)

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

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 degree jet boundary indicate that the station of greatest pressure fluctuations is determined by the jet velocity and the radial distance, with a tendency of the maximum to shift downstream as either parameter is increased.
Date: February 19, 1954
Creator: Lassiter, Leslie W. & Hubbard, Harvey H.
System: The UNT Digital Library
A Thermal Equation for Flame Quenching (open access)

A Thermal Equation for Flame Quenching

"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 the flame reaction, with small correction necessitated by the effect of pressure on flame temperature" (p. 1).
Date: December 6, 1954
Creator: Potter, A. E., Jr. & Berlad, A. L.
System: The UNT Digital Library
A theoretical study of the effect of forward speed on the free-space sound-pressure field around propellers (open access)

A theoretical study of the effect of forward speed on the free-space sound-pressure field around propellers

Report presenting an analysis of the sound-pressure field of a rotating propeller in forward flight in free space by replacing the normal-pressure distribution over the propeller associated with thrust and torque by a distribution of acoustic pressure doublets acting at the propeller disk. The result is presented for a moving and a fixed observer.
Date: 1954
Creator: Garrick, I. E. & Watkins, Charles E.
System: The UNT Digital Library
An Analysis of Pressure Studies and Experimental and Theoretical Downwash and Sidewash Behind Five Pointed-Tip Wings at Supersonic Speeds (open access)

An Analysis of Pressure Studies and Experimental and Theoretical Downwash and Sidewash Behind Five Pointed-Tip Wings at Supersonic Speeds

"Flow-angle and pressure surveys behind five, thin, pointed-tip wings of varying plan form have been made at Mach numbers 1.62 and 2.41. Schlieren studies at a Mach number 1.93 for the same five plan-form wings were made to illustrate the behavior of the vortex sheet. The surveys were conducted at 1.5, 3, and 4 root chords behind three triangular wings of 50 degree, 63 degree, and 72 degree leading-edge sweep angle, and behind the 50 degree triangular wing reversed" (p. 1067).
Date: January 22, 1954
Creator: Boatright, William B.
System: The UNT Digital Library
A comparative analysis of the performance of long-range hypervelocity vehicles (open access)

A comparative analysis of the performance of long-range hypervelocity vehicles

From Summary: "Long-range hypervelocity vehicles are studied in terms of their motion in powered flight. Powered flight is analyzed for an idealized propulsion system which approximates rocket motors. Unpowered flight is characterized by a return to earth along a ballistic, skip, or glide trajectory. Only those trajectories are treated which yield the maximum range for a given velocity at the end of powered flight. Aerodynamic heating is treated in a manner similar to that employed previously by the senior authors in studying ballistic missiles (NACA rep. 1381), with the exception that radiant as well as convective heat transfer is considered in connection with glide and skip vehicles."
Date: December 10, 1954
Creator: Eggers, Alfred J., Jr.; Allen, H. Julian & Neice, Stanford E.
System: The UNT Digital Library
A Summary of Preliminary Investigations Into the Characteristics of Combustion Screech in Ducted Burners (open access)

A Summary of Preliminary Investigations Into the Characteristics of Combustion Screech in Ducted Burners

"Increasing demands for higher afterburner performance have required operation at progressively higher fuel-air ratios, which has increased the occurrence and intensity of screeching combustion. The onset of screech may be followed by rapid destruction of the combustor shell and other combustor parts. Because of its destructive characteristics, considerable effort has been expended to understand and eliminate screech. NACA work on the screeching combustion problem prior to 1954 is summarized herein" (p. 1195).
Date: February 8, 1954
Creator: Lewis Laboratory Staff
System: The UNT Digital Library
Behavior of materials under conditions of thermal stress (open access)

Behavior of materials under conditions of thermal stress

A review is presented of available information on the behavior of brittle and ductile materials under conditions of thermal stress and thermal shock. For brittle materials, a simple formula relating physical properties to thermal-shock resistance is derived and used to determine the relative significance of two indices currently in use for rating materials. For ductile materials, thermal-shock resistance depends upon the complex interrelation among several metallurgical variables which seriously affect strength and ductility. These variables are briefly discussed and illustrated from literature sources. The importance of simulating operating conditions in tests for rating materials is especially to be emphasized because of the importance of testing conditions in metallurgy. A number of practical methods that have been used to minimize the deleterious effects of thermal stress and thermal shock are outlined.
Date: 1954
Creator: Manson, S. S.
System: The UNT Digital Library
Effect of Variable Viscosity and Thermal Conductivity on High-Speed Slip Flow Between Concentric Cylinders (open access)

Effect of Variable Viscosity and Thermal Conductivity on High-Speed Slip Flow Between Concentric Cylinders

"Schamberg was the first to solve the differential equations of slip flow, including the Burnett terms, for concentric circular cylinders assuming constant coefficients of viscosity and thermal conductivity. The problem is solved for variable coefficients of viscosity and thermal conductivity in this paper by applying a transformation which leads to an iteration method. Starting with the solution for constant coefficients, this method enables one to approximate the solution for variable coefficients very closely after one or two steps" (p. 435).
Date: 1954
Creator: Lin, T. C. & Street, R. E.
System: The UNT Digital Library
Structural Response to Discrete and Continuous Gusts of an Airplane Having Wing Bending Flexibility and a Correlation of Calculated and Flight Results (open access)

Structural Response to Discrete and Continuous Gusts of an Airplane Having Wing Bending Flexibility and a Correlation of Calculated and Flight Results

"An analysis is made of the structural response to gusts of an airplane having the degrees of freedom of vertical motion and wing bending flexibility and basic parameters are established. A convenient and accurate numerical solution of the response equations is developed for the case of discrete-gust encounter, an exact solution is made for the simpler case of continuous-sinusoidal-gust encounter, and the procedure is outlined for treating the more realistic condition of continuous random atmospheric turbulence, based on the methods of generalized harmonic analysis. Correlation studies between flight and calculated results are then given to evaluate the influence of wing bending flexibility on the structural response to gusts of two twin-engine transports and one four-engine bomber" (p. 1).
Date: March 4, 1954
Creator: Houbolt, John C. & Kordes, Eldon E.
System: The UNT Digital Library
Formation and Combustion of Smoke in Laminar Flames (open access)

Formation and Combustion of Smoke in Laminar Flames

"The nature and formation of smoke and its combustion were investigated. Smoke, which consist of tiny mesomorphous crystals tightly packed into popcorn-ball-like particles that agglomerate to give filaments, was found to contain about 5 percent of the hydrogen originally present in the fuel. Factors affecting smoke formation were studied in both diffusion flames and premixed Bunsen flames. It is suggested that smoking tendency increases with increasing stability of the carbon skeleton of the molecule, as determined by relative bond strength" (p. 657).
Date: August 17, 1954
Creator: Schalla, Rose L.; Clark, Thomas P. & McDonald, Glen E.
System: The UNT Digital Library
A Study of Hypersonic Small-Disturbance Theory (open access)

A Study of Hypersonic Small-Disturbance Theory

"A systematic study is made of the approximate inviscid theory of thin bodies moving at such high supersonic speeds that nonlinearity is an essential feature of the equations of flow. The first-order small-disturbance equations are derived for three-dimensional motions involving shock waves, and estimates are obtained for the order of error involved in the approximation. The hypersonic similarity rule of Tsien and Hayes, and Hayes' unsteady analogy appear in the course of the development" (p. 1).
Date: 1954
Creator: Van Dyke, Milton D.
System: The UNT Digital Library
An analytical study of the effect of airplane wake on the lateral dispersion of aerial sprays (open access)

An analytical study of the effect of airplane wake on the lateral dispersion of aerial sprays

From the Introduction: "In the present reports the paths of liquid spray droplets issued in the flow field behind an airplane are calculated."
Date: 1954
Creator: Reed, Wilmer H., III
System: The UNT Digital Library
Performance and Boundary-Layer Data From 12 Degree and 23 Degree Conical Diffusers of Area Ratio 2.0 at Mach Numbers Up to Choking and Reynolds Numbers Up to 7.5 X 10(6) (open access)

Performance and Boundary-Layer Data From 12 Degree and 23 Degree Conical Diffusers of Area Ratio 2.0 at Mach Numbers Up to Choking and Reynolds Numbers Up to 7.5 X 10(6)

"For each of two inlet-boundary-layer thicknesses, performance and boundary-layer characteristics have been determined for a 12 degree, 10-inch-inlet-diameter diffuser, a 12 degree, 21-inch-inlet-diameter diffuser, and a 23 degree, 21-inch-inlet-diameter diffuser. The investigation covered an inlet Mach number range from about 0.10 to coking. The corresponding inlet Reynolds number, based on inlet diameter, varied from about 0.5 x 10(6) to 7.5 x 10(6)" (p. 1013).
Date: November 15, 1954
Creator: Little, B. H., Jr. & Wilbur, Stafford W.
System: The UNT Digital Library
Charts Relating the Compressive Buckling Stress of Longitudinally Supported Plates to the Effective Deflectional and Rotational Stiffness of the Supports (open access)

Charts Relating the Compressive Buckling Stress of Longitudinally Supported Plates to the Effective Deflectional and Rotational Stiffness of the Supports

"A stability analysis is made of a long flat rectangular plate subjected to a uniform longitudinal compressive stress and supported along its longitudinal edges and along one or more longitudinal lines by elastic line supports. The elastic supports possess deflectional and rotational stiffness. Such configuration is an idealization of the compression cover skin and internal structure of a wing and tail surfaces" (p. 1).
Date: 1954
Creator: Anderson, Roger A. & Semonian, Joseph W.
System: The UNT Digital Library