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Comparison of Yaw Characteristics of a Single-Engine Airplane Model With Single-Rotating and Dual-Rotating Propellers

Description: Report presenting testing in the pressure tunnel to determine the yaw characteristics of a scale model of a single-engine, fighter-type airplane with six-blade single-rotating and dual-rotating propellers. Force and moment characteristics are presented for several model and power conditions.
Date: April 1944
Creator: Neely, R. H.; Fogarty, L. E. & Alexander, S. R.
Partner: UNT Libraries Government Documents Department
open access

Effect of the Lift Coefficient on Propeller Flutter

Description: Report presenting flutter of propellers at high angles of attack and flutter data obtained in connection with tests of models of large wind-tunnel propellers. The stall flutter speed was found to be much lower than the calculated classical flutter speed. That flutter speed is only obtainable if the propeller operates at the ideal angle of zero twist.
Date: July 1945
Creator: Theodorsen, Theodore & Regier, Arthur A.
Partner: UNT Libraries Government Documents Department
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Propeller Selection From Aerodynamic Considerations

Description: Report presenting a theoretical analysis of the performance of propellers extending to high values. Charts are presented that facilitate the selection of the most efficient propellers over a wide range of operating conditions.
Date: July 1942
Creator: Crigler, John L. & Talkin, Herbert W.
Partner: UNT Libraries Government Documents Department
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Flight Investigation at High Speeds of Profile Drag of Wing of a P-47d Airplane Having Production Surfaces Covered With Camouflage Paint

Description: Report presenting a flight investigation made at high speeds to determine the profile drag of a P-47D airplane wing with production surfaces covered with camouflage paint. The results indicated that a minimum profile-drag coefficient of 0.0097 was attained for lift coefficients from 0.16 to 0.25 at Mach numbers less than 0.67.
Date: March 1946
Creator: Zalovcik, John A. & Daum, Fred L.
Partner: UNT Libraries Government Documents Department
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Flight Investigation of Boundary-Layer and Profile-Drag Characteristics of Smooth Wing Sections of a P-47D Airplane

Description: Report presenting a flight investigation made of boundary-layer and profile-drag characteristics of smooth wing sections of a P-47D airplane. Measurements were made at three stations on the wing: boundary-layer measurements, pressure-distribution measurements, and wake surveys. The results indicated that a minimum profile-drag coefficient of 0.0062 for the smooth section at 63 percent semispan was obtained.
Date: October 1945
Creator: Zalovcik, John A.
Partner: UNT Libraries Government Documents Department
open access

Flight Investigation of Boundary-Layer Control by Suction Slots on an NACA 35-215 Low-Drag Airfoil at High Reynolds Numbers

Description: Report presenting an investigation of the effectiveness of suction slots as a means of extending the laminar boundary layer in flight at high Reynolds numbers on an NACA 35-215 airfoil. The results showed that, with a slot spacing of about 5 percent of the chord, the laminar boundary layer could be maintained to or slightly beyond 45 percent of the chord.
Date: February 1944
Creator: Zalovcik, John A.; Wetmore, J. W. & von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department
open access

Tests of a Heated Low-Drag Airfoil

Description: Report discusses the results of an experimental investigation into the NACA 65,2-016 heated wing. Information about the effect of heating on the drag coefficients, Reynolds numbers, and stability of the laminar boundary layer.
Date: December 1942
Creator: Frick, Charles W., Jr. & McCullough, George B.
Partner: UNT Libraries Government Documents Department
open access

Flight Investigation of Boundary-Layer Transition and Profile Drag of an Experimental Low-Drag Wing Installed on a Figher-Type Airplane

Description: Report presenting a boundary-layer-transition and profile-drag investigation conducted on an experimental low-drag wing installed on a P-47 airplane designated the XP-47F. Measurements were made at a section outside the propeller slipstream with smooth and with standard camouflage surfaces and on the upper surface of a section in the propeller slipstream with the surface smoothed. Results regarding the right wing section outside the slipstream and left wing section in the propeller slipstream a… more
Date: April 1945
Creator: Zalovcik, John A. & Skoog, Richard B.
Partner: UNT Libraries Government Documents Department
open access

A Profile-Drag Investigation in Flight on an Experimental Fighter-Type Airplane the North American XP-51

Description: Report discussing the results of an investigation of the North American XP-51 and its low-drag airfoils. Several surface conditions were tested and the profile-drag coefficients were determined. The surface that was smoothened and faired by filling and sanding had the lowest profile-drag coefficient.
Date: November 1942
Creator: Zalovcik, John A.
Partner: UNT Libraries Government Documents Department
open access

Investigation of the Behavior of Parallel Two-Dimensional Air Jets

Description: Report presenting an investigation made of the flow downstream from a two-dimensional grid, formed of parallel rods. The two-dimensional character of the flow was insured by end plates normal to the rods and covering the entire flow field. The nature of the flow was determined primarily by means of total-head measurements.
Date: November 1944
Creator: Corrsin, Stanley
Partner: UNT Libraries Government Documents Department
open access

Extension of Useful Operating Range of Axial-Flow Compressors by Use of Adjustable Stator Blades

Description: "A theory has been developed for resetting the blade angles of an axial-flow compressor in order to improve the performance at speeds and flows other than the design and thus extend the useful operating range of the compressor. The theory is readily applicable to the resetting of both rotor and stator blades or to the resetting of only the stator blades and is based on adjustment of the blade angles to obtain lift coefficients at which the blades will operate efficiently. Calculations were made… more
Date: December 29, 1944
Creator: Sinnette, John T., Jr. & Voss, William J.
Partner: UNT Libraries Government Documents Department
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Occurrence of Iron Oxides on Cast-Iron Engine Surfaces After Operation

Description: Report presenting an examination of the surfaces of used cast-iron piston rings from various single-cylinder aircraft engine tests by electron diffraction. Generally, the oxide patterns were obtained to an appreciable extent from only the top compression ring of the piston-ring assembly; the other rings gave predominately a graphite pattern.
Date: February 1946
Creator: Nowick, A. S. & Brockway, L. O.
Partner: UNT Libraries Government Documents Department
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Generalized equations for selection charts for heat exchangers in aircraft

Description: "The equations that describe the operation of a heat exchanger - the equations for pressure drop, rate of heat transfer, and power expenditure - have been put into nondimensional, generalized form. These generalized equations can be used for constructing selection charts for various types of aircraft heat exchangers. Such charts would facilitate choice of heat-exchanger dimensions for any given set of operating conditions. A typical selection chart is presented" (p. 1).
Date: April 1942
Creator: Tifford, Arthur N. & Wood, George P.
Partner: UNT Libraries Government Documents Department
open access

Knock-limited performance of several internal coolants

Description: Report presenting the effect of internal cooling on the knock-limited performance of AN-F-28 fuel in a CFR engine with the following internal coolants: water, methyl alcohol-water mixture, ammonia-methyl alcohol-water mixture, monomethyllamine-water mixture, dimethylamine-water mixture, and trimethylamine-water mixture.
Date: February 1944
Creator: Bellman, Donald R. & Evvard, John C.
Partner: UNT Libraries Government Documents Department
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Oxygen boosting of an aircraft-engine cylinder in conjunction with internal coolants

Description: Report presenting an investigation to determine the possibility of attaining or approaching critical-altitude power at altitudes considerably higher than the critical as limited by the supercharger by the use of oxygen in conjunction with internal coolants.
Date: April 1944
Creator: Spencer, Robert C.; Jones, Anthony W. & Pfender, John F.
Partner: UNT Libraries Government Documents Department
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The reduction of nonuseful pressure losses on air-cooled engine cylinders by means of improved finning and baffling

Description: Report presenting an analysis of the pressure drop that is required to cool a typically baffled radial engine, which shows that a total pressure drop of 58 pounds per square foot is necessary at sea level and 112 pounds per square foot is required at an altitude of 40,000 feet.
Date: February 1943
Creator: Wood, George P.
Partner: UNT Libraries Government Documents Department
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Cylinder Barrel Cooling With Bonded Preformed Copper Fins

Description: Report presenting testing of preformed copper fins which were furnace-brazed to a steel-cylinder barrel. The barrel was electrically heated and blower-cooled to determine heat overall heat-transfer coefficient. Information regarding potential future adaptations of the fins are provided.
Date: May 1941
Creator: Foster, H. H. & Ellerbrock, H. H., Jr.
Partner: UNT Libraries Government Documents Department
open access

Charts for Helicopter-Performance Estimation

Description: Report presenting charts relating helicopter aerodynamic design variables to performance in steady powered flight. The flight conditions covered are hovering, climb, and horizontal flight. The use of the charts is illustrated by numerical examples in order that computations can be made for particular problems.
Date: August 1945
Creator: Talkin, Herbert W.
Partner: UNT Libraries Government Documents Department
open access

Efficiency tests of a single-stage impulse turbine having an 11.0-inch pitch-line diameter wheel with air as the driving fluid

Description: Report presenting efficiency tests on a single-stage impulse turbine with an 11.0-inch pitch-line diameter wheel and a fabricated nozzle diaphragm with air at moderate temperature as the driving fluid. Results regarding the variation of turbine efficiency with blade-to-jet speed ratio over a range of turbine pressure ratios and maximum efficiency are provided.
Date: April 1945
Creator: Gabriel, David S. & Carman, L. Robert
Partner: UNT Libraries Government Documents Department
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The Effect of Inlet Pressure and Temperature on the Efficiency of a Single Stage Impulse Turbine Having an 11.0-Inch Pitch-Line Diameter Wheel

Description: Efficiency tests have been conducted on a single-stage impulse engine having an 11-inch pitch-line diameter wheel with inserted buckets and a fabricated nozzle diaphragm. The tests were made to determine the effect of inlet pressure, Inlet temperature, speed, and pressure ratio on the turbine efficiency. An analysis is presented that relates the effect of inlet pressure and temperature to the Reynolds number of the flow. The agreement between the analysis and the experimental data indicates tha… more
Date: June 1945
Creator: Gabriel, David S.; Carman, L. Robert & Trautwein, Elmer E.
Partner: UNT Libraries Government Documents Department
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Charts for estimation of the characteristics of a helicopter rotor in forward flight I: profile drag-lift ratio for untwisted rectangular blades

Description: Report presenting charts showing the rotor profile drag-lift ratio for a helicopter rotor operating in forward flight and having hinged rectangular untwisted blades. The charts are given for a range of power input covering glides, level flight, and moderate rates of climb. A drag curve was used for preparing the charts, and the curve is compared with experimental curves for typical airfoils.
Date: August 1944
Creator: Bailey, F. J., Jr.
Partner: UNT Libraries Government Documents Department
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Cooling Characteristics of a Pratt and Whitney R-2800 Engine Installed in an NACA Short-Nose High-Inlet-Velocity Cowling

Description: An investigation was made of the cooling characteristics of a P and W R-2800 engine with NACA short-nose high inlet-velocity cowling. The internal aerodynamics of the cowling were studied for ranges of propeller-advance ratio and inlet-velocity ratio obtained by deflection of cowling flaps. Tests included variations of engine power, fuel/air ratio and cooling-air pressure drop. Engine cooling data are presented in the form of cooling correlation curves, and an example for calculation of cooling… more
Date: June 1944
Creator: Corson, Blake W. & McLellan, Charles H.
Partner: UNT Libraries Government Documents Department
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Experimental Study of the Coating Formed on Nitrided-Steel Piston Rings During Operation in Nitrided-Steel Cylinders

Description: Report presenting a study of nitrided-steel piston rings in nitrided-steel cylinder barrels, which showed material of high reflectivity on their running faces. The structure of the material could not be resolved at a magnification of 1500 diameters. Results regarding the occurrence of coating, thickness of coating, height of coating above the nominal surface, chemical characteristics, physical characteristics, metallurgical change, and additional tests are provided.
Date: March 1944
Creator: Bobrowsky, A. R.; Kittel, J. Howard & Boegli, Charles P.
Partner: UNT Libraries Government Documents Department
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