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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

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

Aerodynamic heating and the deflection of drops by an obstacle in an air stream in relation to aircraft icing

Description: From Summary: "Two topics of interest to persons attempting to apply the heat method of preventing ice formation on aircraft are considered. Surfaces moving through air at high speed are shown, both theoretically and experimentally, to be subject to important aerodynamic heating effects that will materially reduce the heat required to prevent ice. Numerical calculations of the path of water drops in an air stream around a circular cylinder are given. From these calculations, information is obtained on the percentage of the swept area cleared of drops."
Date: October 1940
Creator: Kantrowitz, Arthur

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.

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 number, M, corresponds to conditions in the wind-tunnel test section with the model removed (p. 1.).
Date: January 1, 1943
Creator: Nitzberg, Gerald E

Emergency measures for increasing the range of fighter airplanes

Description: From Summary: "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 indicated that the wing-tip extensions were the most promising of the devices considered."
Date: May 1943
Creator: Jones, Robert T. & Wetmore, Joseph W.

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.