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Performance Charts for a Turbojet System

Description: Convenient charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet system. These charts take into account the effects of ram pressure, compressor pressure ratio, ratio of combustion-chamber-outlet temperature to atmospheric temperature, compressor efficiency, turbine efficiency, combustion efficiency, discharge-nozzle coefficient, losses in total pressure in the inlet to the jet-propulsion unit and in the combustion chamber, and variation in specific heats with temperature. The principal performance charts show clearly the effects of the primary variables and correction charts provide the effects of the secondary variables. The performance of illustrative cases of turbojet systems is given. It is shown that maximum thrust per unit mass rate of air flow occurs at a lower compressor pressure ratio than minimum specific fuel consumption. The thrust per unit mass rate of air flow increases as the combustion-chamber discharge temperature increases. For minimum specific fuel consumption, however, an optimum combustion-chamber discharge temperature exists, which in some cases may be less than the limiting temperature imposed by the strength temperature characteristics of present materials.
Date: June 1947
Creator: Pinkel, Benjamin & Karp, Irving M.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests and analysis of three 10-foot-diameter three-blade tractor propellers differing in pitch distribution

Description: Report discussing an investigation of the effect of variations in pitch distribution on propeller efficiency at low Mach numbers. The three 10-foot-diameter propellers tested consisted of three blades mounted on a streamline body and were tested for a blade-angle range from 15 degrees to 60 degrees. Information about the propeller thrust, power coefficients, force-balance measurements, and total pressure in the propeller wake is provided.
Date: August 1946
Creator: Gilman, Jean, Jr.
Partner: UNT Libraries Government Documents Department

Progress report on strength and creep of special ceramic bodies in tension at elevated temperatures

Description: Report presenting an investigation for the determination of the behavior of ceramic bodies in tension at elevated temperatures for the purpose of determining data for the design of ceramic blades for gas turbines. Observations were made of six special ceramic bodies in order to determine their tensile strength and creep during prolonged loading under a range of stresses and temperatures.
Date: June 1946
Creator: Geller, R. F. & Burdick, M. D.
Partner: UNT Libraries Government Documents Department

Column and plate compressive strengths of aircraft structural materials: Extruded 14S-T aluminum alloy

Description: From Summary: "Column and plate compressive strengths of extruded 14S-T aluminum alloy were determined both within and beyond the elastic range from tests of flat-end H-section columns and from local-instability tests of H-, Z-, and channel-section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures."
Date: May 1946
Creator: Heimerl, George J. & Niles, Donald E.
Partner: UNT Libraries Government Documents Department

Analysis of Effect of Rolling Pull-Outs on Wing and Aileron Loads of a Fighter Airplane

Description: An analysis was made to determine the effect of rolling pull-out maneuvers on the wing and aileron loads of a typical fighter airplane, the P-47B. The results obtained indicate that higher loads are imposed upon wings and ailerons because of the rolling pull-out maneuver, than would be obtained by application of the loading requirements to which the airplane was designed. An increase of 102 lb or 15 percent of wing weight would be required if the wing were designed for rolling pull-out maneuver. It was also determined that the requirements by which the aileron was originally designed were inadequate.
Date: March 1946
Creator: Pearson, Henry A. & Aiken, William S.
Partner: UNT Libraries Government Documents Department

Comparison of Wind-Tunnel and Flight Measurements of Stability and Control Characteristics of a Douglas A-26 Airplane

Description: Tests in Langley pressure tunnel of model XA-26 bomber were compared with those of A-26B (twin-engine attack bomber) and showed that static longitudinal stability, indicated by elevator-fixed neutral points, and variation of elevator deflection in straight and turning flight were good. Airplane possessed improved stability at low speeds which was attributed to pronounced stalling at root of production wing. At rudder-force reversal at speeds higher than those in flight tests, agreement in rudder-fixed and rudder-free static directional stability was good. Hinge moment obtained at zero sideslip was satisfactory for determining aileron forces in sideslip.
Date: March 1, 1946
Creator: Koven, William & Kayten, Gerald G.
Partner: UNT Libraries Government Documents Department

Determination of towline tension and stability of spin-recovery parachutes

Description: Report presenting testing of a number of spin-recovery parachutes varying in size in order to determine the force exerted by the parachutes on the towline and the stability of the parachutes. The effects of modifications to the parachutes regarding towline tension and stability are also provided. Results regarding the parachute motions, air forces on parachutes, shock loads, and effects of modifications to line length and canopy vent are provided.
Date: March 1946
Creator: Wood, John H.
Partner: UNT Libraries Government Documents Department

The Knock-Limited Performance of Fuel Blends Containing Aromatics V : N-Propylbenzene, N-Butylbenzene, Isobutylbenzene, M-Xylene, and 1-Isopropyl-4-Methylbenzene

Description: Results are reported of knock-limited tests of five aromatics, each individually blended with selected base fuels and tested with and without TEL, using 17.6, F-4, and F-3 small-scale engines. The five aromatics rated in the following order of decreasing antiknock effectiveness at fuel/air ratio 0.10: m-xylene, 1-isopropyl-4-methylbenzene, n-propylbenzene, isobutylbenzene, and n-butylbenzene.
Date: March 1, 1946
Creator: Meyer, Carl L. & Branstetter, J. Robert
Partner: UNT Libraries Government Documents Department

Test-stand investigation of cooling characteristics and factors affecting temperature distribution of a double-row aircraft engine

Description: Report presenting testing of a double-row radial air-cooled engine to investigate overall cooling characteristics and to analyze what variations in temperature distribution were caused by variations in cooling-air pressure drop, power, and fuel-air ratio. Testing occurred over a range of engine powers.
Date: March 1946
Creator: Sipko, Michael A.; Hickel, Robert O. & Jones, Robert J.
Partner: UNT Libraries Government Documents Department

Flight Measurements to Determine Effect of a Spring-Loaded Tab on Longitudinal Stability of an Airplane

Description: In conjunction with a program of research on the general problem of stability of airplanes in the climbing condition, tests have been made of a spring-loaded tb which. is referred to as a ?springy tab,? installed on the elevator of a low-wing scout bomber. The tab was arranged to deflect upward with decrease in speed which caused an increase in the pull force required to trim at low speeds and thereby increased the stick-free static longitudinal stability of the airplane. It was found that the springy tab would increase the stick-free stability in all flight conditions, would reduce the danger of inadvertent stalling because of the definite pull force required to stall the airplane with power on, would reduce the effect of center-of-gravity position on stick-free static stability, and would have little effect on the elevator stick forces in accelerated f11ght. Another advantage of the springy tab is that it might be used to provide almost any desired variation of elevator stick force with speed by adjusting the tab hinge-moment characteristics and the variation of spring moment with tab deflection. Unlike the bungee and the bobweight, the springy tab would provide stick-free static stability without requiring a pull force to hold the stick back while taxying. A device similar to the springy tab may be used on the rudder or ailerons to eliminate undesirable trim-force variations with speed.
Date: February 1, 1946
Creator: Hunter, Paul A. & Reeder, John P.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics of plain and balanced flaps on an NACA 0009 elliptical semispan wing

Description: Report discusses a series of force tests of a NACA 0009 elliptical semispan wing equipped with a flap that is either 50 percent of the wing area or 30 percent of the wing area. Information about the lift, hinge moment, and drag and pitching moment is provided.
Date: February 1946
Creator: Tamburello, Vito; Smith, Bernard J. & Silvers, H. Norman
Partner: UNT Libraries Government Documents Department

An analysis of the skipping characteristics of some full-size flying boats

Description: From Introduction: "The purpose of this report is to gather together in one place information on the skipping characteristics of number of flying boats. A graph showing the influence of the hull form on the skipping characteristics is given which should be useful in laying out the proportions of the hull in preliminary design to insure good landing behavior."
Date: January 1946
Creator: Locke, F. W. S., Jr.
Partner: UNT Libraries Government Documents Department