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Some Recent Contributions to the Study of Transition and Turbulent Boundary Layers

Description: Report presenting a paper in two parts about transition and turbulent boundary layers. The first part reviews the current problem of the instability of laminar boundary layers. The second part reviews the current state of knowledge of the mechanics of turbulent boundary layers and of the methods now being used for fundamental studies of the turbulent fluctuations in turbulent boundary layers.
Date: April 1947
Creator: Dryden, Hugh L.
Partner: UNT Libraries Government Documents Department

Considerations of the Total Drag of Supersonic Airfoil Sections

Description: The results of calculations of the viscous and pressure drags of some two-dimensional supersonic airfoils at zero lift are presented. The results indicate that inclusion of viscous drag alters many previous results regarding the desirability of certain airfoil shapes for securing low drags at supersonic speeds. At certain Reynolds and Mach numbers, for instance, a circular-arc airfoil may theoretically have less drag than the previously advocated symmetrical wedge-shape profile; although under different conditions, the circular-arc airfoil may have a higher drag.
Date: July 1947
Creator: Ivey, H. Reese & Klunker, E. Bernard
Partner: UNT Libraries Government Documents Department

Two-Dimensional Irrotational Transonic Flows of a Compressible Fluid

Description: The methods of NACA TN No. 995 have been slightly modified and extended in include flows with circulation by considering the alteration of the singularities of the incompressible solution due to the presence of the hypergeometric functions in the analytic continuation of the solution. It was found that for finite Mach numbers the only case in which the nature of the singularity can remain unchanged is for a ratio of specific heats equal to -1. From a study of two particular flows it seems that the effect of geometry cannot be neglected, and the conventional "pressure-correction" formulas are not valid, even in the subsonic region if the body is thick, especially if there is a supersonic region in the flow.
Date: June 1948
Creator: Kuo, Yung-Huai
Partner: UNT Libraries Government Documents Department

Tables and charts of flow parameters across oblique shocks

Description: Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy.
Date: August 1948
Creator: Neice, Mary M.
Partner: UNT Libraries Government Documents Department

Two-dimensional subsonic compressible flows past arbitrary bodies by the variational method

Description: Instead of solving the nonlinear differential equation which governs the compressible flow, an approximate method of solution by means of the variational method is used. The general problem of steady irrotational flow past an arbitrary body is formulated. Two examples were carried out, namely, the flow past a circular cylinder and the flow past a thin curved surface. The variational method yields results of velocity and pressure distributions which compare excellently with those found by existing methods. These results indicate that the variational method will yield good approximate solution for flow past both thick and thin bodies at both high and low Mach numbers.
Date: March 1951
Creator: Wang, Chi-Teh
Partner: UNT Libraries Government Documents Department

Performance of B. M. W. 185-horsepower airplane engine

Description: Report discusses the results of testing on a B.M.W. engine in an altitude chamber where temperature and pressure can be controlled to simulate flight at various altitudes. Results for various engine speeds, altitudes, and propeller speeds are provided.
Date: April 13, 1922
Creator: Sparrow, Stanwood Willston
Partner: UNT Libraries Government Documents Department

Tables for the Computation of Wave Drag of Arrow Wings of Arbitrary Airfoil Section

Description: Tables and computing instructions for the rapid evaluation of the wave drag of delta wings and of arrow wings having a ration of the tangent of the trailing-edge sweep angle to the tangent of the leading-edge sweep angle in the range from -1.0 to 0.8. The tables cover a range of both subsonic and supersonic leading edges.
Date: June 1954
Creator: Grant, Fredrick C. & Cooper, Morton
Partner: UNT Libraries Government Documents Department

Average Outside-Surface Heat-Transfer Coefficients and Velocity Distributions for Heated and Cooled Impulse Turbine Blades in Static Cascades

Description: Heat-transfer investigation conducted on cooled as well heated impulse-type turbine blades in a static cascade to determine the effect of direction of heat flow on convective heat-transfer coefficients.
Date: March 9, 1951
Creator: Hubbartt, James E. & Schum, Eugene F.
Partner: UNT Libraries Government Documents Department

Charts for the Computation of Equilibrium Composition of Chemical Reactions in the Carbon-Hydrogen-Nitrogen System at Temperatures from 2000 to 5000 Degrees K

Description: Charts are provided for the estimation and progressive adjustment of two independent variables on which the calculations are based. Additional charts are provided for the graphical calculation of the composition.
Date: July 1948
Creator: Huff, Vearl N. & Calvert, Clyde S.
Partner: UNT Libraries Government Documents Department

An investigation of a thermal ice-prevention system for a C-46 cargo airplane III: description of thermal ice-prevention equipment for wings, empennage, and windshield

Description: Report presenting an investigation of a thermal ice-prevention system for a Curtiss-Wright C-46 airplane, including the equipment for the wings, empennage, and windshield. The report is the third in a series and focuses on the revisions to the components for thermal ice prevention, the temperature- and pressure-measurement equipment installed in the airplane to determine the performance of the system, and the results of static-load structural tests of a specimen of the wing outer-panel leading edge.
Date: February 1945
Creator: Jones, Alun R. & Spies, Ray J., Jr.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters IX: measured and predicted performance of two exhaust gas-air heat exchangers and an apparatus for evaluating exhaust gas-air heat exchangers

Description: Report presenting laboratory testing to determine the thermal output and pressure drop characteristics of the Airesearch and Solar fluted-type exhaust gas-air heat exchangers. The apparatus used in these tests consisted of a natural gas furnace of 3,000,000 Btu per hour thermal capacity, a centrifugal blower, and a system of ducting and various measuring devices. Results regarding the method of analysis, the Airesearch heat exchanger tests, the solar heat exchanger tests, and a comparison of the two heat exchangers are provided.
Date: March 1943
Creator: Boelter, L. M. K.; Miller, M. A.; Sharp, W. H.; Morrin, E. H.; Iversen, H. W. & Mason, W. E.
Partner: UNT Libraries Government Documents Department

Investigation of the aerodynamic characteristics of the NACA RM-10 missile (with fins) at a Mach number of 1.62 in the Langley 9-inch supersonic tunnel

Description: Report presenting an investigation of a fin-stabilized scale model of the NACA RM-10 missile at a Mach number of 1.62. Measurements were made of the lift, drag, and pitching moment of the finned body over a range of angles of attack. Comparisons with the results from other testing facilities are also provided.
Date: December 19, 1952
Creator: Coletti, Donald E.
Partner: UNT Libraries Government Documents Department

A low-speed experimental investigation of the effect of a sandpaper type of roughness on boundary-layer transition

Description: Report describing the effects of an area of roughness on the velocity and turbulence measurements of an airfoil. It details the effects of the size, location, and height of the roughness on the Reynolds number. From Summary: "An investigation was made in the Langley low-turbulence pressure tunnel to determine the effect of size and location of a sandpaper type of roughness on the Reynolds number for transition."
Date: 1958
Creator: Horton, Elmer A. & von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department

Flight Tests of Modifications to Improve the Aileron Control Characteristics of a North American XP-51 Airplane (AC No. 41-38)

Description: Investigations were undertaken to improve the ailerons of a P-51 fighter so as to obtain greater effectiveness without increasing the stick forces. Modifications consisted of increasing the deflection range of the aileron to 70 percent and changing the original concave section to a thick section with beveled trailing edge. Results of the modified ailerons showed an increase in effectiveness over the original aileron of 70 percent at low speed and 55 percent at high speeds.
Date: June 1942
Creator: White, M. D. & Hoover, Herbert H.
Partner: UNT Libraries Government Documents Department

Further measurements of normal accelerations on racing airplanes

Description: This report details the acceleration data collected from racing airplanes during actual races. The data was collected in order to make recommendations regarding the structural safety of racing airplanes and the methods of operating racing airplanes that reduces the probability of subjecting them to extreme air loads. The records do not lead to any conclusions regarding maximum air loads.
Date: February 1936
Creator: Kirschbaum, H. W. & Scudder, N. F.
Partner: UNT Libraries Government Documents Department

Fuel-evaporation loss as determined by the change in the specific gravity of the fuel in an aircraft fuel tank

Description: Report discusses the results of an investigation to determine the feasibility of using the change in the specific gravity of fuels in aircraft fuel tanks to measure fuel-vaporization loss. Six fuels were tested via fuel-distillation tests and simulated-flight tests. An equation based on the specific gravity of the fuel is also described.
Date: May 1945
Creator: Stone, Charles S. & Kramer, Walter E.
Partner: UNT Libraries Government Documents Department

The effect of exhaust-stack shape on the design and performance of the individual cylinder exhaust-gas jet-propulsion system

Description: Report presenting tests on a single-cylinder, air-cooled engine to determine the effect of several different exhaust-stack shapes on the design and performance of the individual cylinder exhaust-gas jet-propulsion systems. Results regarding the effect of nozzle area and stack shape on exhaust-gas jet thrust, effect of nozzle area and stack shape on overall performance for the S-shape, the 90 degree bend, and the 180 degree bend, the effect on the shape on engine power and volumetric efficiency, and the effect of a branched stack on engine power are provided.
Date: November 1942
Creator: Turner, L. Richard & Humble, Leroy V.
Partner: UNT Libraries Government Documents Department

The effect of cowling on cylinder temperatures and performance of a Wright J-5 engine

Description: This report presents the results of tests conducted to determine the effect of different amounts and kinds of cowling on the performance and cylinder temperatures of a standard Wright J-5 engine. These tests were conducted in conjunction with drag and propeller tests in which the same cowlings were used. Four different cowlings were investigated varying from the one extreme of no cowling on the engine to the other extreme of the engine completely cowled and the cooling air flowing inside the cowling through an opening in the nose and out through an annular opening at the rear of the engine. Each cowling was tested at air speeds of approximately 60, 80, and 100 miles per hour.
Date: May 2, 1929
Creator: Schey, Oscar W. & Biermann, Arnold E.
Partner: UNT Libraries Government Documents Department