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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.
open access

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 … more
Date: July 1947
Creator: Ivey, H. Reese & Klunker, E. Bernard
open access

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 … more
Date: June 1948
Creator: Kuo, Yung-Huai
open access

Charts for the Computation of Equilibrium Composition of Chemical Reactions in the Carbon-Hydrogen-Oxygen-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.
open access

Analysis of Wind-Tunnel Stability and Control Tests in Terms of Flying Qualities in Full-Scale Airplanes

Description: From Summary: "The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicate the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for … more
Date: October 1943
Creator: Kayten, Gerald G.
open access

The Measurement of Fuel-Air Ratio by Analysis for the Oxidized Exhaust Gas

Description: "An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Fi… more
Date: 1943
Creator: Gerrish, Harold C. & Meem, J. Lawrence, Jr.
open access

Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel

Description: Report presenting testing to obtain experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. Testing occurred over a wide range of air flows and density altitudes.
Date: July 1944
Creator: Goldstein, Arthur W. & Ellerbrock, Herman H., Jr.
open access

The Knock-Limited Performance of S Reference Fuel Plus 2 Milliliters of Triethylthallium Per Gallon

Description: Report discusses the results of testing of thallium as an antiknock agent in an internal-combustion engine. From Introduction: "On a weight basis, the thallium vapors were found to have several times the antiknock value of tetraethyl lead, which was added to the fuel. The amount of thallium vapor necessary to raise the antiknock properties of a gasoline up to exact equivalence with a benzol-gasoline mixture was determined in these engine tests."
Date: November 1945
Creator: Meyer, Carl L.
open access

A method for studying the hunting oscillations of and airplane with a simple type of automatic control

Description: Report presenting a method for predicting the amplitude and frequency, under certain simplifying conditions, of the hunting oscillations of an automatically controlled aircraft with lag in the control system or in response of the aircraft to the controls. Formulas are given expressing the response to a variation of signal in terms of response to a unit signal.
Date: May 1944
Creator: Jones, Robert T.
open access

Intercooler cooling-air weight flow and pressure drop for minimum drag loss

Description: Report presenting an analysis of the power losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give minimum total power loss for any given cooling effectiveness. The investigation covers a range of flight conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and adiabatic efficiency.
Date: April 1944
Creator: Reuter, J. George & Valerino, Michael F.
open access

Correlation of exhaust-valve temperatures with engine operating conditions and valve design

Description: Report presenting a theory regarding engine-cooling variables from a previous report, which was used as a basis for the development of a semi-empirical equation to correlate exhaust-valve temperature with engine conditions. Results regarding the determination of constants, influences of operating variables on mean effective gas temperatures, thermal-resistance factor, and accuracy of correlating equation are provided.
Date: October 1945
Creator: Zipkin, M. A. & Sanders, J. C.
open access

Experiments on Drag of Revolving Disks, Cylinders and Streamline Rods at High Speeds

Description: Report presenting an experimental investigation concerned primarily with the extension of test data on the drag of revolving disks, cylinders, and streamline rods to high Mach numbers and Reynolds numbers. The tests generally confirm earlier theories and add in some new results. One of the primary findings of interest is that skin friction does not depend on Mach number.
Date: June 1944
Creator: Theodorsen, Theodore & Regier, Arthur
open access

The effect of compressibility on two-dimensional tunnel-wall interference for a symmetrical airfoil

Description: Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach numb… more
Date: May 1943
Creator: Nitzberg, Gerald E.
open access

A method for determining the rate of heat transfer from a wing or streamline body

Description: From Summary: "A method for calculating the rate of heat transfer from the surface of an airfoil or streamline body is presented. A comparison with the results of an experimental investigation indicates that the accuracy of the method is good. This method may be used to calculate the heat supply necessary for heat de-icing or in ascertaining the heat loss from the fuselage of an aircraft operating at great altitude, for example."
Date: December 1942
Creator: Frick, Charles W., Jr. & McCullough, George B.
open access

Emergency Measures for Increasing the Range of Fighter Airplanes

Description: "An analysis was made to show the relative effectiveness of streamline external fuel tanks, a fuel tank in the form of a wing mounted in a biplane position, and auxiliary wing panels attached at the wing tips to increase the span as temporary means for increasing the range of a fighter-type airplane. Figures and charts for the various devices considered show the results of calculations of range, duration of flight, and take-off distance for both land-base and carrier operation. The results indi… more
Date: May 1943
Creator: Jones, Robert T. & Wetmore, Joseph W.
open access

Review of Flight Tests of NACA C and D Cowlings on the XP-42 Airplane

Description: Report presenting the results of flight tests of the performance and cooling characteristics of three NACA D cowlings and of a conventional NACA C cowling on the XP-42 airplane. The D cowling is, generally, characterized by the use of an annular inlet and diffuser section for the engine-cooling air. An increase in maximum speed was noted in the XP-42 airplane due to the change from a C cowling to a D cowling.
Date: April 1943
Creator: Johnston, J. Ford
open access

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.
open access

Fluid de-icing tests on a Chandler-Evans 1900 CPB-3 carburetor mounted on a Pratt & Whitney R-1830-C4 intermediate rear engine section

Description: Report presenting an investigation of the icing and de-icing characteristics of a Pratt & Whitney R-1830 engine induction system. The current report covers a program to determine the most effective rate and method of injection of de-icing fluid to remove a heavy ice formation from the induction system. Results regarding the flow rates, recovery times, de-icing portions of the runs, and ice formation characteristics are provided.
Date: October 1944
Creator: Galvin, Herman B. & Essex, Henry A.
open access

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.
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