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A preliminary evaluation of the explosion jet-propulsion engine

Description: Report investigating the theoretical sea-level performance of an explosion jet-propulsion engine similar to the German flying bomb to show the effects on performance of heat added and supercharging and a comparison was drawn between the performance of the explosion engine and the constant-pressure engine. The explosion engine was found to be more efficient than the constant-pressure engine at compressor pressure ratios below 3.0 when the maximum gas temperature of the constant-pressure engine is 1600 degrees Fahrenheit.
Date: August 1944
Creator: Sanders, J. C.
Partner: UNT Libraries Government Documents Department

Correlation of exhaust-valve temperatures with engine operating conditions and valve design in an air-cooled cylinder

Description: A semiempirical equation correlating exhaust-valve temperatures with engine operating conditions and exhaust-valve design has been developed. The correlation is based on the theory correlating engine and cooling variables developed in a previous NACA report. In addition to the parameters ordinarily used in the correlating equation, a term is included in the equation that is a measure of the resistance of the complex heat-flow paths between the crown of the exhaust valve and a point on the outside surface of the cylinder head. A means for comparing exhaust valves of different designs with respect to cooling is consequently provided. The necessary empirical constants included in the equation were determined from engine investigations of a large air-cooled cylinder. Tests of several valve designs showed that the calculated and experimentally determined exhaust-valve temperatures were in good agreement.
Date: October 1, 1945
Creator: Zipkin, M. A. & Sanders, J. C.
Partner: UNT Libraries Government Documents Department

A preliminary study of a propeller powered by gas jets issuing from the blade tips

Description: From Summary: "Computations are made of the performance of a propeller designed to develop 56 thrust horsepower at 100 miles per hour. The fuel consumption of the jet-operated propeller would be considerably higher than that of a reciprocating engine and a propeller. The lighter weight of the jet-operated propeller will result in a lighter weight of engine plus fuel for short-range flights. A theoretical analysis is made of a propeller powered by gas jets issuing from the blade tips."
Date: November 1946
Creator: Sanders, J. C. & Sanders, N. D.
Partner: UNT Libraries Government Documents Department

Analysis of variation of piston temperature with piston dimensions and undercrown cooling

Description: From Summary: "A theoretical analysis is presented that permits estimation of the changes in piston-temperature distribution induced by variations in the crown thickness, the ring-groove-pad thickness, and the undercrown surface heat-transfer coefficient. The analysis consists of the calculation of operating temperatures at various points in the piston body on the basis of the experimentally determined surface heat-transfer coefficients and boundary-region temperatures, as well as arbitrarily selected surface coefficients."
Date: January 15, 1948
Creator: Sanders, J. C. & Schramm, W. B.
Partner: UNT Libraries Government Documents Department

Theoretical Evaluation of Methods of Cooling the Blades of Gas Turbines

Description: A study was made of heat transfer in turbine blades and the effects on blade temperature of cooling the blade root and tip, changing the dimensions of the blades, raising the cycle temperatures, insulating with ceramics, and cooling by circulation of air or water through hollow blades.
Date: February 11, 1947
Creator: Sanders, J. C. & Mendelson, Alexander
Partner: UNT Libraries Government Documents Department

Calculations of the Performance of a Compression-Ignition Engine-Compressor Turbine Combination 1: Performance of a Highly Supercharged Compression-Ignition Engine

Description: From Summary: "Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm."
Date: December 1945
Creator: Sanders, J. C. & Mendelson, Alexander
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

Operating temperatures of a sodium-cooled exhaust valve as measured by a thermocouple

Description: Report presents the results of a thermocouple installed in the crown of a sodium-cooled exhaust valve. The valve was tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 degrees F. was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 r.p.m. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear-spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.
Date: 1943
Creator: Sanders, J. C.; Wilsted, H. D. & Mulcahy, B. A.
Partner: UNT Libraries Government Documents Department

Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

Description: A thermocouple was installed in the crown of a sodium-cooled exhaust valve. The valve was then tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 F was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 rpm. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.
Date: December 1, 1943
Creator: Sanders, J. C.; Wilsted, H. D. & Mulcahy, B. A.
Partner: UNT Libraries Government Documents Department

Comparison of hovering performance of helicopters powered by jet-propulsion and reciprocating engines

Description: Report presenting an investigation of the maximum hovering time, or the time that a helicopter can sustain itself without motion, for helicopters using a reciprocating engine, by ramjet engines at the tips of rotor blades, and by pulse-jet engines at the tips of rotor blades. Testing showed that the reciprocating engine permitted much longer hovering time than the jet-propulsion engines, but the jet-propulsion engines were much lighter and could lift greater disposable loads.
Date: June 11, 1948
Creator: Brightwell, Virginia L.; Peters, Max D. & Sanders, J. C.
Partner: UNT Libraries Government Documents Department

Cooling tests of an air-cooled engine cylinder with copper fins on the barrel

Description: Report presenting the results of comparative cooling tests run on two Wright C9GC (G-200) cylinders, one with the original steel fins and one with 1-inch spiral copper fins brazed on the barrel. Calculations were also performed using copper and aluminum fins with the same weight as the original steel fins, which showed positive results. Results regarding cylinder-temperature correlation, piston-temperature correlation, and comparative performance are also provided.
Date: July 1942
Creator: Sanders, J. C.; Wilsted, H. D. & Mulcahy, B. A.
Partner: UNT Libraries Government Documents Department

The Effect of Continuous Knock on the Endurance of an Aircraft Engine Cylinder

Description: Report presenting an investigation to determine any injurious effects of knock on engine parts. Endurance tests were run on a single-cylinder engine to compare the conditions of cylinders operated with and without knock. Results regarding the history of the tests, conditions of pistons and cylinders, absence of surface ignition, and effect of knock on cylinder temperatures are provided.
Date: March 1944
Creator: Sanders, J. C.; Hilgendorf, J. A. & Peters, M. D.
Partner: UNT Libraries Government Documents Department