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The Reaction Jet as a Means of Propulsion at High Speeds

Description: Report presenting a simple equation that can be used to facilitate the appraisal of the conventional jet as a means of propulsion. The equation can be used to estimate the performance of a large variety of aeropropulsive devices. The results using this equation indicate that attainable propulsive efficiencies at high speeds below sonic velocity are certain to be lower than is common at low speeds with the conventional propeller.
Date: June 1941
Creator: Williams, David T.
Partner: UNT Libraries Government Documents Department

Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels

Description: The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described.
Date: September 14, 1953
Creator: Tower, Leonard K. & Gammon, Benson E.
Partner: UNT Libraries Government Documents Department

A method for evaluating the effects of drag and inlet pressure recovery on propulsion-system performance

Description: Report presenting a method of evaluating the ratio of aircraft thrust minus drag to ideal thrust for any inlet pressure recovery for airplanes with air-breathing propulsion systems. The qualities required for the evaluation include flight Mach number and altitude, engine total-pressure ratio and total-temperature ratio, engine air-flow requirements, and airplane drag.
Date: August 1954
Creator: Kremzier, Emil J.
Partner: UNT Libraries Government Documents Department

Adaptation of Combustion Principles to Aircraft Propulsion, Volume 1, Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

Description: The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.
Date: April 1, 1955
Creator: Barnett, Henry C. & Hibbard, Robert R.
Partner: UNT Libraries Government Documents Department

Flight and Test-Stand Investigation of High-Performance Fuels in Modified Double-Row Radial Air-Cooled Engines 3: Knock-Limited Performance of 33-R as Compared with a Triptane Blend and 28-R in Flight

Description: "A comparison has been made in flight of the antiknock characteristics of 33-R fuel with that of 28-R and a triptane blend. The knock-limited performance of the three fuels - 33-R, a blend of 80 percent 28-R plus 20 percent triptane (leaded to 4.5 ml TEL/gal), and 28-R - was investigated in two modified 14-cylinder double-row radial air-cooled engines. Tests were conducted on the engines as installed in the left inboard nacelle of an airplane. A carburetor-air temperature of approximately 85 deg F was maintained" (p. 1).
Date: August 1945
Creator: Blackman, Calvin C. & White, H. Jack
Partner: UNT Libraries Government Documents Department

Preliminary Results of Nene II Engine Altitude-Chamber Performance Investigation 2 - Altitude Performance Using 18.41-Inch Diameter-Jet Nozzle

Description: "An investigation is being conducted to determine the altitude performance characteristics of the Nene II engine and its components. The present paper presents preliminary results obtained using a jet nozzle of 18.41 inches in diameter, giving an area equal to 96.4 percent of the area of the standard jet nozzle of this engine. The test results presented are for conditions simulating altitudes from seal level to 50,000 feet and ram-pressure ratios from 1.00 to 2.70. The ram pressure ratios correspond to flight Mach numbers between zero and 1.28" (p. 1).
Date: June 14, 1948
Creator: Armstrong, John C.; Wilsted, H. Dean & Vincent, Kenneth R.
Partner: UNT Libraries Government Documents Department

Tandem Air Propellers - 2

Description: "Tests of three-blade, adjustable-pitch counterrotating tandem model propellers, adjusted to absorb equal power at maximum efficiency of the combination, were made at Stanford University. The aerodynamic characteristics, for blade-angle settings of 15, 25, 35, 45, 55, and 65 degrees at 0.75R of the forward propeller and for diameters spacings of 8-1/2, 15 and 30% were compared with those of three-blade and six-blade propellers of the same blade form. It was found that, in order to realize the condition of equal power at maximum efficiency, the blade angles for the rear propeller must be generally less than for the forward propeller, the difference increasing the blade angle" (p. 1).
Date: October 1939
Creator: Lesley, E. P.
Partner: UNT Libraries Government Documents Department

Some Effects of Rapid Inlet Pressure Oscillation on the Operation of a Turbojet Engine

Description: "A program was conducted in an altitude facility at the NACA Lewis laboratory to investigate the effects of rapid inlet pressure oscillations on the operation of a current turbo jet engine. These pressure oscillations were approximately sinusoidal in form and were generated to cover a frequency range of 2 to 75 cycles per second and an amplitude range of 10 to 70 percent of the free-stream total pressure. As the oscillation progressed through the compressor, the amplitude was attenuated considerably and a relatively large phase shift (lag) occurred" (p. 1).
Date: January 7, 1958
Creator: Russey, Robert E. & Lubick, Robert J.
Partner: UNT Libraries Government Documents Department

Simulated Altitude Investigation of Stewart-Warner Model 906-B Combustion Heater

Description: "An investigation has been conducted to determine thermal and pressure-drop performance and the operational characteristics of a Stewart-Warner model 906-B combustion heater. The performance tests covered a range of ventilating-air flows from 500 to 3185 pounds per hour, combustion-air pressure drops from 5 to 35 inches of water, and pressure altitudes from sea level to 41,000 feet. The operational characteristics investigated were the combustion-air flows for sustained combustion and for consistent ignition covering fuel-air ratios ranging from 0.033 to 0.10 and pressure altitudes from sea level to 45,000 feet" (p. 1).
Date: January 1947
Creator: Ebersbach, Frederick R. & Cervenka, Adolph J.
Partner: UNT Libraries Government Documents Department

Tests of Two-Blade Propellers in the Langley 8-Foot High-Speed Tunnel to Determine the Effect on Propeller Performance of a Modification of Inboard Pitch Distribution

Description: "Tests of two propellers having two blades and differing only in the inboard pitch distribution were made in the Langley 8-foot highspeed tunnel to determine the effect of inboard pitch distribution on propeller performance. Propeller was designed for operation in the reduced velocity region ahead of an NACA cowling; the inboard pitch distribution of the modified propeller was increased for operation at or near free-stream velocities, such as would be obtained in a pusher installation. Conditions covering climb, cruise, and high-speed operation" (p. 1).
Date: February 1951
Creator: Delano, James B. & Carmel, Melvin M.
Partner: UNT Libraries Government Documents Department

Summary of Investigations of Mark 25 Aerial-Torpedo Turbine

Description: "The power plant from a Mark 25 aerial torpedo was investigated both as a two-stage turbine and as a single-stage modified turbine to determine the effect on overall performance of nozzle size and shape, first-stage rotor-blade configuration, and axial nozzle-rotor running clearance. Performance was evaluated in terms of brake, rotor, and blade efficiencies. All the performance data were obtained for inlet total to outlet static pressure ratios of 8, 15 (design), and 20 with inlet conditions maintained constant at 95 pounds per square inch gage and 1000 F for rotor speeds from approximately 6000 to 18,000 rpm" (p. 1).
Date: 1950-03?
Creator: Schum, Harold J.; Whitney, Warren J. & Buckner, Howard A., Jr.
Partner: UNT Libraries Government Documents Department

Effect of Maximum Cruise-Power Operation at Ultra-Lean Mixture and Increased Spark Advance on the Mechanical Condition of Cylinder Components

Description: "A continuous 50-hour test was conducted to determine the effect of maximum cruise-power operation at ultra-lean fuel-air mixture and increased spark advance on the mechanical conditions of cylinder components. The test was conducted on a nine-cylinder air-cooled radial engine at the following conditions:brake horsepower, 750; engine speed, 1900 rpm; brake mean effective pressure, 172 pounds per square inch; fuel-air ratio, 0.052; spark advance, 30 deg B.T.C.; and maximum rear-spark-plug-bushing temperature, 400 F. In addition to the data on corrosion and wear, data are presented and briefly discussed on the effect of engine operation at the conditions of this test on economy, knock, preignition, and mixture distribution" (p. 1).
Date: September 27, 1945
Creator: Harris, Herbert B.; Duffy, Robert T. & Erwin, Robert D., Jr.
Partner: UNT Libraries Government Documents Department

Effect of Various Methods of Boundary-Layer Control on Performance of V-1710-93 Engine-Stage Supercharger

Description: "Four methods of boundary-layer control were tried during an investigation to improve the flow in the impeller passages of a V-1710-93 engine-stage supercharger. The boundary layer along the impeller front shroud was removed by suction. In one method the removal was accomplished by recirculation of the air to the impeller inlet; in another method, by external removal. In the other methods, slots were cut through the impeller-blade faces first at 30 percent and then at 30 and 70 percent of the mean-flow-path length measured from leading edges of the rotating inlet guide vanes to introduce air from the high-pressure side of the blades into the region where stagnation and separation were suspected" (p. 1).
Date: January 1947
Creator: Kohl, Robert C. & Diggs, Donald R.
Partner: UNT Libraries Government Documents Department

Engine Operation in Flight for Minimum Fuel Consumption

Description: "Engine and airplane performance data have been gathered from various sources and analyzed to determine indications of the most economical methods of flight operation from a consideration of fuel expenditure. The analysis includes the influence of such facts as fuel-air ratio, engine speed, engine knock, altitude, cylinder cooling, spark timing, and limits of cruising brake mean effective pressure. The results indicate that the cheapest power is obtained with approximately correct mixture at low engine speed and highest permissible manifold pressure" (p. 1).
Date: November 1939
Creator: Reuter, George
Partner: UNT Libraries Government Documents Department

Experimental Determination of Exhaust Gas Thrust, Special Report

Description: "This investigation presents the results of tests made on a radial engine to determine the thrust that can be obtained from the exhaust gas when discharged from separate stacks and when discharged from the collector ring with various discharge nozzles. The engine was provided with a propeller to absorb the power and was mounted on a test stand equipped with scales for measuring the thrust and engine torque. The results indicate that at full open throttle at sea level, for the engine tested, a gain in thrust horsepower of 18 percent using separate stacks, and 9.5 percent using a collector ring and discharge nozzle, can be expected at an air speed of 550 miles per hour" (p. 1).
Date: February 1940
Creator: Pinkel, Benjamin & Voss, Fred
Partner: UNT Libraries Government Documents Department

Effect of Rotor- and Stator-Blade Modifications on Surge Performance of an 11-Stage Axial-Flow Compressor 1 - Original Production Compressor of XJ40-WE-6 Engine

Description: "An investigation to increase the compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine at high equivalent speeds was conducted at the NACA Lewis altitude wind tunnel. This report evaluates the compressor modifications which were restricted to (1) twisting rotor blades (in place) to change blade section angles and (2) inserting new stator diaphragms with different blade angles. Such configuration changes could be incorporated quickly and easily in existing engines at overhaul depots" (p. 1).
Date: June 18, 1952
Creator: Finger, Harold B.; Essig, Robert H. & Conrad, E. William
Partner: UNT Libraries Government Documents Department

Effect of Turbine Axial Nozzle-Wheel Clearance on Performance of Mark 25 Torpedo Power Plant

Description: "Investigations were made of the turbine from a Mark 25 torpedo to determine the performance of the unit with three different turbine nozzles at various axial nozzle-wheel clearances. Turbine efficiency with a reamed nondivergent nozzle that uses the axial clearance space for gas expansion was little affected by increasing the axial running clearance from 0.030 to 0.150 inch. Turbine efficiency with cast nozzles that expanded the gas inside the nozzle passage was found to be sensitive to increased axial nozzle-wheel clearance" (p. 1).
Date: February 4, 1948
Creator: Hoyt, Jack W. & Kottas, Harry
Partner: UNT Libraries Government Documents Department

Drag and Propulsive Characteristics of Air-Cooled Engine-Nacelle Installations for Large Airplanes, Special Report

Description: "An investigation is in progress in the NACA full-scale wind tunnel to determine the drag and propulsive efficiency of nacelle sizes. In contrast with the usual tests with a single nacelle, these tests were conducted with nacelle-propeller installations on a large model of a 4-engine airplane. Data are presented on the first part of the investigation, covering seven nacelle arrangements with nacelle diameters from 0.53 to 1.5 times the wing thickness" (p. 1).
Date: August 1939
Creator: Silverstein, Abe & Wilson, Herbert A., Jr.
Partner: UNT Libraries Government Documents Department

Recent Results in Rocket Flight Technique

Description: "The concept of the effective ejection velocity of a rocket engine is explained and the magnitude of the attainable ejection velocity theoretically and experimentally investigated. Velocities above 3000 meters per second (6700 mph) are actually measured and the possibilities of further increases shown" (p. 1).
Date: April 1942
Creator: Sänger, Eugen
Partner: UNT Libraries Government Documents Department

Computed Temperature Distribution and Cooling of Solid Gas-Turbine Blades

Description: "Computations were made to determine the temperature distribution and cooling of solid gas-turbine blades.A range of temperatures was used from 1500 degrees to 2500 degrees F, blade-root temperatures from 100 degrees to 1000 degrees F, blade thermal conductivity from 8 to 220 BTU/(hr)(sq ft)(degrees F/ft), and net gas to metal heat transfer coefficients from 75 to 250 BTU/(hr)(sq ft)(degrees F)" (p. 1).
Date: February 11, 1947
Creator: Reuter, J. George & Gazley, Carl, Jr.
Partner: UNT Libraries Government Documents Department

Correlation of the Characteristics of Single-Cylinder and Flight Engines in Tests of High-Performance Fuels in an Air-Cooled Engine 1 - Cooling Characteristics

Description: Variable charge-air flow, cooling-air pressure drop, and fuel-air ration investigations were conducted to determine the cooling characteristics of a full-scale air-cooled single cylinder on a CUE setup. The data are compared with similar data that were available for the same model multicylinder engine tested in flight in a four-engine airplane. The cylinder-head cooling correlations were the same for both the single-cylinder and the flight engine. The cooling correlations for the barrels differed slightly in that the barrel of the single-cylinder engine runs cooler than the barrel of te flight engine for the same head temperatures and engine conditions.
Date: October 4, 1945
Creator: Wilson, Robert W.; Richard, Paul H. & Brown, Kenneth D.
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines 6 - Computed Temperature Distribution Through Cross Section of Water-Cooled Turbine Blade

Description: "A theoretical analysis of the cross-sectional temperature distribution of a water-cooled turbine blade was made using the relaxation method to solve the differential equation derived from the analysis. The analysis was applied to specific turbine blade and the studies icluded investigations of the accuracy of simple methods to determine the temperature distribution along the mean line of the rear part of the blade, of the possible effect of varying the perimetric distribution of the hot gas-to -metal heat transfer coefficient, and of the effect of changing the thermal conductivity of the blade metal for a constant cross sectional area blade with two quarter inch diameter coolant passages" (p. 1).
Date: May 1, 1947
Creator: Livingood, John N. B. & Sams, Eldon W.
Partner: UNT Libraries Government Documents Department

Control Performance of General Electric Fuel and Torque Regulator Operating on T31-3 Turbine-Propeller Engine in Sea-Level Test Stand

Description: "A General Electric fuel and torque regulator was tested in conjunction with a T31-3 turbine-propeller engine in the sea-level static test stand at the NACA Lewis laboratory. The engine and control were operated over the entire speed range: 11,000 rpm, nominal flight idle, to 13,000 rpm, full power. Steady-state and transient data were recorded and are presented with a description of the four control loops being used in the system" (p. 1).
Date: August 29, 1951
Creator: Oppenheimer, Frank L. & Lazar, James
Partner: UNT Libraries Government Documents Department