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Performance of two air-cooled turbojet engines determined analytically from engine component performance for a range of cooling-air weight flows

Description: Report presenting an analysis of two turbojet engines, including the component performance of the compressors and turbines, in order to determine the effect on engine performance and operation of bleeding the compressor to furnish cooling air for the turbine rotor blades. Results regarding the compressor and turbine performance characteristics and engine performance characteristics are provided.
Date: February 18, 1954
Creator: Ziemer, Robert R.; Schafer, Louis J., Jr. & Heaton, Thomas R.
Partner: UNT Libraries Government Documents Department

The problem of cooling an air-cooled cylinder on an aircraft engine

Description: An analysis of the cooling problem has been to show by what means the cooling of an air-cooled aircraft engine may be improved. Each means of improving cooling is analyzed on the basis of effectiveness in cooling with respect to power for cooling. The altitude problem is analyzed for both supercharged and unsupercharged engines. The case of ground cooling is also discussed. The heat-transfer process from the hot gases to the cylinder wall is discussed on the basis of the fundamentals of heat transfer and thermodynamics. Adiabatic air-temperature rise at a stagnation point in compressible flow is shown to depend only on the velocity of flow.
Date: April 22, 1940
Creator: Brevoort, M. J. & Joyner, U. T.
Partner: UNT Libraries Government Documents Department

Full-scale tests of NACA cowlings

Description: A comprehensive investigation has been carried on with full-scale models in the NACA 20-foot wind tunnel, the general purpose of which is to furnish information in regard to the physical functioning of the composite propeller-nacelle unit under all conditions of take-off, taxiing, and normal flight. This report deals exclusively with the cowling characteristics under condition of normal flight and includes the results of tests of numerous combinations of more than a dozen nose cowlings, about a dozen skirts, two propellers, two sizes of nacelle, as well as various types of spinners and other devices.
Date: May 18, 1936
Creator: Theodorsen, Theodore; Brevoort, M. J. & Stickle, George W.
Partner: UNT Libraries Government Documents Department

Internal film cooling experiments in 4-inch duct with gas temperatures to 2000 degrees F

Description: Report presenting an investigation of the cooling effectiveness of water films on the inner surface of a well-insulated, 4-inch-diameter duct with air flowing through the duct at a range of temperature and Reynolds numbers. Results regarding the effect of the gas temperature and mass velocity on liquid-cooled length, effect of coolant flow on liquid-cooled length, and some suggestions for further investigation are provided. Equations for correlation are created from the data.
Date: September 21, 1950
Creator: Kinney, George R. & Sloop, John L.
Partner: UNT Libraries Government Documents Department

A Preliminary Study of Ram-Actuated Cooling Systems for Supersonic Aircraft

Description: An analysis has been made of the characteristics of several cooling cycles suitable for cockpit cooling of supersonic aircraft. All the cycles considered utilize the difference between dynamic and ambient static pressure to actuate the cooling system and require no additional power source. The results of the study indicate that as flight speeds become greater, increasingly complex systems are required to reduce the altitudes above approximately 35,000 feet, a system composed of an externally loaded expansion turbine in conjunction with a supersonic diffuser would maintain tolerable ventilating air temperature, at least up to a flight Mach number of 2. The most complex system considered,composed of compressor, intercooler, and expansion turbine with the intercooler cooling air decreased in temperature by expansion through an auxiliary turbine is capable of maintaining a ventilation air temperature less than ambient temperature up to a flight Mach number of 3.7.
Date: April 29, 1947
Creator: Stalder, Jackson R. & Wadleigh, Kenneth R.
Partner: UNT Libraries Government Documents Department

Design charts for cross-flow tubular intercoolers charge-across-tube type

Description: Report presenting equations relating the various dimensions, air mass flow, and performance of a cross-flow tubular intercooler in which the charge flows across and the cooling air through the tubes. Design charts are presented from which the intercooler design characteristics and performance can be quickly determined.
Date: January 1941
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

Design charts for cross-flow tubular intercoolers charge-through-tube type

Description: Report presenting equations relating the various dimensions, air weight flow, and performance of a cross-flow tubular intercooler in which the charge flows through and the cooling air across the tubes. A method of determining and presenting the performance of a given intercooler at various operating conditions is indicated. Results regarding the cooling effectiveness equation, effect of primary intercooler variables, design charts, effect of tube arrangement on intercooler characteristics, and performance charts are provided.
Date: July 1941
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

Comparison of Intercooler Characteristics

Description: Report presenting a method of comparing the performance, weight, and general dimensional characteristics of intercoolers. The performance and dimensional characteristics covered in the comparisons include cooling effectiveness, pressure drops and weight flows of the charge and cooling air, power losses, volume, frontal area, and width.
Date: November 1942
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

An investigation of diffuser-resistance combinations in duct systems

Description: Report presenting an investigation to determine the properties of diffuser-resistance combinations. The work applies to the design of airplane cooling ducts in which air is expanded in front of resistances, such as radiators, oil coolers, intercoolers, or the cylinders of an air-cooled engine.
Date: February 1942
Creator: McLellan, Charles H. & Nichols, Mark R.
Partner: UNT Libraries Government Documents Department

High-altitude flight cooling investigation of a radial air-cooled engine

Description: Report presenting an investigation of the cooling of an 18-cylinder, twin-row, radial, air-cooled engine in a high-performance pursuit airplane for variable engine and flight conditions at a range of altitudes to provide a basis for predicting high-altitude cooling performance from sea-level or low-altitude test results.
Date: August 1946
Creator: Manganiello, Eugene J.; Valerino, Michael F. & Bell, E. Barton
Partner: UNT Libraries Government Documents Department

An experimental investigation of rectangular exhaust-gas ejectors applicable for engine cooling

Description: "An experimental investigation of rectangular exhaust-gas ejector pumps was conducted to provide data that would serve as a guide to the design of ejector applications for aircraft engines with marginal cooling. The pumping characteristics of rectangular ejectors actuated by the exhaust of a single-cylinder aircraft engine were determined for a range of ejector mixing-section area from 20 to 50 square inches, over-all length from 12 to 42 inches, aspect ratio from 1 to 5, diffusing exit area from 20 to 81 square inches, and exhaust-nozzle aspect ratio from 1 to 42" (p. 161).
Date: May 1, 1944
Creator: Manganiello, Eugene J. & Bogatsky, Donald
Partner: UNT Libraries Government Documents Department

High-altitude flight cooling investigation of a radial air-cooled engine

Description: "An investigation of the cooling of an 18-cylinder, twin-row, radial, air-cooled engine in a high-performance pursuit airplane has been conducted for variable engine and flight conditions at altitudes ranging from 5000 to 35,000 feet in order to provide a basis for predicting high-altitude cooling performance from sea-level or low altitude experimental results. The engine cooling data obtained were analyzed by the usual NACA cooling-correlation method wherein cylinder-head and cylinder-barrel temperatures are related to the pertinent engine and cooling-air variables. A theoretical analysis was made of the effect on engine cooling of the change of density of the cooling air across the engine (the compressibility effect), which becomes of increasing importance as altitude is increased" (p. 267).
Date: May 9, 1946
Creator: Manganiello, Eugene J.; Valerino, Michael F. & Bell, E. Barton
Partner: UNT Libraries Government Documents Department

Piston temperatures in an air-cooled engine for various operating conditions

Description: As part of a program for the study of piston cooling, this report presents the results of tests conducted on a single-cylinder, air-cooled, carburetor engine to determine the effect of engine operating conditions on the temperatures at five locations on the piston.
Date: April 6, 1940
Creator: Manganiello, Eugene J.
Partner: UNT Libraries Government Documents Department

Rapid determination of core dimensions of crossflow gas-to-gas heat exchangers

Description: Report presenting a generalized procedure that permits a rapid determination of the core lengths of crossflow gas-to-gas heat exchangers. Some of the variables that must be prescribed include the inlet states of each fluid, the available pressure drops for each fluid, the required temperature change of one fluid, the fluid heat capacities, and the core configuration.
Date: December 1956
Creator: Diaguila, Anthony J. & Livingood, John N. B.
Partner: UNT Libraries Government Documents Department

Study of ram-air heat exchangers for reducing turbine cooling-air temperature of a supersonic aircraft turbojet engine

Description: The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude of 70,000 feet. A compressor-bleed-air weight flow of 2.7 pounds per second was assumed for the coolant; ram air was considered as the other fluid. Pressure drops and inlet states of both fluids were prescribed, and ranges of compressor-bleed-air temperature reductions and of the ratio of compressor-bleed to ram-air weight flows were considered.
Date: August 3, 1956
Creator: Diaguila, Anthony J.; Livingood, John N. B. & Eckert, Ernst R. G.
Partner: UNT Libraries Government Documents Department

The effect of altitude on cooling

Description: Report presenting variables that control the cooling of liquid-cooled and air-cooled engines and then to show by illustrations how either engine may be cooled at any desired altitude. Cooling was found to not be the limiting factor in the design of high-altitude airplanes and was also not found to be a valid reason for selecting either liquid- or air-cooled engines for high-altitude operation.
Date: March 1943
Creator: Brevoort, Maurice J.; Joyner, Upshur T. & Wood, George P.
Partner: UNT Libraries Government Documents Department

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

Pressure available for cooling with cowling flaps

Description: Report presents the results of a full-scale investigation conducted in the NACA 20-foot tunnel to determine the pressure difference available for cooling with cowling flaps. The flaps were applied to an exit slot of smooth contour at 0 degree flap angle. Flap angles of 0 degree, 15 degrees, and 30 degrees were tested. Two propellers were used; propeller c which has conventional round blade shanks and propeller f which has airfoil sections extending closer to the hub. The pressure available for cooling is shown to be a direct function of the thrust disk-loading coefficient of the propeller.
Date: May 9, 1940
Creator: Stickle, George W.; Naiman, Irven & Crigler, John L.
Partner: UNT Libraries Government Documents Department

Effect of Exhaust Pressure on the Cooling Characteristics of a Liquid-Cooled Engine

Description: "Data for a liquid-cooled engine with a displacement volume of 1710 cubic inches were analyzed to determine the effect of exhaust pressure on the engine cooling characteristics. The data covered a range of exhaust pressures from 7 to 62 inches of mercury absolute, inlet-manifold pressures from 30 to 50 inches of mercury absolute, engine speeds from 1600 to 3000 rpm, and fuel-air ratios from 0.063 to 0.100. The effect of exhaust pressure on engine cooling was satisfactorily incorporated in the NACA cooling-correlation method as a variation in effective gas temperature with exhaust pressure. Large variations of cylinder-head temperature with exhaust pressure were obtained for operation at constant charge flow" (p. 1).
Date: January 22, 1947
Creator: Doyle, Ronald B. & Desmon, Leland G.
Partner: UNT Libraries Government Documents Department

Correlation of single-cylinder cooling tests of a Pratt and Whitney R-2800-21 engine cylinder with wind-tunnel tests of a Pratt and Whitney R-2800-27 engine

Description: Report presenting an equation in which it is possible to correlate the cooling characteristics of an engine. Results regarding engine cooling, engine performance, and estimated cooling-pressure-drop requirements are provided.
Date: December 1943
Creator: Ellerbrock, Herman H., Jr.
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

An Investigation of the Ranger V-770-8 Engine Installation for the Edo XOSE-1 Airplane 1: Cooling

Description: Engine temperature data and cooling correlating analyses of the engine and oil cooler are presented in connection with an investigation of the cowling and cooling of the ranger V-770-8 engine installation in the Edo XOSE-1 airplane. Three types of baffles were installed in the course of the tests: the conventional, the turbulent-flow, and the NACA diffuser baffles. Each of the types was of merit in cooling a different region on the cylinder. Incorporation of the best features of the three types into one baffle, a method which appears to be feasible, would provide improvements in cylinder cooling.
Date: October 1945
Creator: Conway, Robert N. & Emmons, M. Arnold, Jr.
Partner: UNT Libraries Government Documents Department

Cooling on the front of an air-cooled engine cylinder in a conventional engine cowling

Description: Measurements were made of the cooling on the fronts of model cylinders in a conventional cowling for cooling in both the ground and the cruising conditions. The mechanisms of front and rear cooling are essentially different. Cooling on the rear baffled part of the cylinders continually increases with increasing fin width. For the front of the cylinder, an optimum fin width was found to exist beyond which an increase in width reduced the heat transfer. The heat transfer coefficient on the front of the cylinders was larger on the side of the cylinder facing the propeller swirl than on the opposite side. This effect became more pronounced as the fin width was increased. These results are introductory to the study of front cooling and show the general effect of several test parameters.
Date: April 5, 1939
Creator: Brevoort, M. J. & Joyner, U. T.
Partner: UNT Libraries Government Documents Department

Cooling tests of a single-row radial engine with several NACA cowlings

Description: The cooling of a single-row radial air-cooled engine using several cowling arrangements has been studied in the NACA 20-foot wind tunnel. The results show the effect of the propeller and several cowling arrangements on cooling for various values of the indicated horsepower in the climb condition. A table giving comparative performance of the various cowling arrangements is presented. The dependence of temperature on indicated horsepower and pressure drop across the baffles is shown by charts. Other charts show the limiting indicated horsepower against the pressure drop across the engine and the heat dissipated at various values of the indicated horsepower.
Date: August 20, 1936
Creator: Brevoort, M. J.; Stickle, George W. & Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department