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Investigation of a Cermet Gas-Turbine-Blade Material of Titanium Carbide Infiltrated With Hastalloy C

Description: A cermet composition was investigated as a potential material for gas-turbine blades. Blades of HS-21 alloy were also operated in the engine simultaneously to provide a basis of comparison. The cermet blades survived as long as approximately 312-1/2 hours at about 1500 degrees F with an average midspan centrifugal stress of approximately 11,500 psi.
Date: January 24, 1955
Creator: Hoffman, Charles A.
Partner: UNT Libraries Government Documents Department

Analytical Investigation of Fuel-Cooled Turbine Blades With Return-Flow Type of Finned Coolant Passages

Description: Memorandum presenting an investigation of coolant-flow rates for a turbine rotor blade with return-flow type of coolant-passage configuration formed by fins within a capped blade shell with both hydrogen and methane fuels as coolants. Results regarding spanwise blade and coolant temperature distributions, effects of coolant inlet temperature on hydrogen-coolant-flow requirements, comparison of return-flow-blade coolant requirements, effect of fin thickness and fin height, comparison of hydrogen and methane as coolants, and feasibility of fuel-cooled turbines are provided.
Date: June 26, 1957
Creator: Nachtigall, Alfred J. & Slone, Henry O.
Partner: UNT Libraries Government Documents Department

Investigations of Slot Configurations for Film-Cooled Turbine Blades by Flow Visualization Methods

Description: Memorandum presenting an investigation on the effectiveness of different slot configurations, which uses the method of making the flow of the cooling air visible. Two methods were used for this purpose: one utilized the traces caused by a reaction between pain spread over the blade surface and a gas mixed with the cooling air, while the second utilized smoke mixed with the cooling air to make it visible. A continuous slot was found to give the best coverage of the cooling-air film.
Date: January 12, 1951
Creator: Eckert, E. R. G.; Jackson, Thomas W. & Francisco, Allen C.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Air-Cooled Turbine Blades in Turbojet Engine 13: Endurance Evaluation of Several Protective Coatings Applied to Turbine Blades of Nonstrategic Steels

Description: Memorandum presenting an investigation of the durabilities of several protective coatings applied to air-cooled gas turbine rotor blades of nonstrategic steels in modified turbojet engines. Four types of coatings (ceramic, nickel, Nicrobraz, and aluminized) were applied to a total of 20 blades.
Date: July 16, 1953
Creator: Bartoo, Edward R. & Clure, John L.
Partner: UNT Libraries Government Documents Department

Analytical determination of local surface heat-transfer coefficients for cooled turbine blades from measured metal temperatures

Description: Analytical methods are presented for the determination of local values of outside and inside heat-transfer coefficients and effective gas temperatures by use of turbine-blade-temperature measurements. The methods are derived for a number of configurations that can be applied to typical cooled-turbine-blade shapes as well as to other types of heat-transfer apparatus.
Date: August 11, 1950
Creator: Brown, W. Byron & Esgar, Jack B.
Partner: UNT Libraries Government Documents Department

Comparison of calculated and experimental temperatures of water-cooled turbine blades

Description: Report presenting analytical methods to calculate average and local turbine-blade temperatures. The temperatures were compared with experimental data obtained in a forced-convection, water-cooled aluminum turbine over a range of turbine-inlet-gas temperatures and coolant-mass velocities. Results regarding comparison of calculated and experimental aluminum turbine blade temperatures, comparison of calculated and experimental stationary-blade temperatures, stationary water-cooled blade operating data, and turbine operating data are provided.
Date: July 15, 1952
Creator: Schum, Eugene F.; Freche, John C. & Stelpflug, William J.
Partner: UNT Libraries Government Documents Department

Additional experimental heat-transfer and durability data on several forced-convection, air-cooled, strut-supported turbine blades of improved design

Description: Report presenting an investigation at the Lewis laboratory to develop air-cooled, strut-supported turbine blades. Six blades were investigated in a full-scale turbojet engine to obtain data on blade durability and blade-cooling effectiveness and strut temperature. Results regarding the heat-transfer investigation and blade-durability investigation are provided.
Date: January 19, 1955
Creator: Schum, Eugene F.
Partner: UNT Libraries Government Documents Department

Investigation of two-stage air-cooled turbine suitable for flight at Mach number of 2.5 1: Velocity-diagram study

Description: Report presenting a two-stage air-cooled turbine configuration and its velocity diagrams for use in the design of blade shapes for a set of engine conditions suitable for flight at Mach number 2.5. The method used to determine the velocity diagrams was one in which the turbine frontal areas and rotor hub inlet and outlet velocities were minimized by varying the hub-tip ratio, turbine- to compressor-tip-diameter ratio, and the work split between the first and second stages.
Date: October 22, 1956
Creator: Miser, James W. & Stewart, Warner L.
Partner: UNT Libraries Government Documents Department

Experimental investigation of air-cooled turbine blades in turbojet engine 9: evaluation of the durability of noncritical rotor blades in engine operation

Description: The durability of five different structural or cooling configurations or combination of both of air-cooled blades made of noncritical materials was investigated in a modified turbojet engine. The greater part of the investigation was conducted at an engine speed of 11,500 rpm, a turbine-inlet temperature of approximately 1670 degrees F, and a cooling-air to combustion gas flow ratio per blade of 0.05. The results of the investigation indicated that air-cooled blades made of noncritical metals can be operated for extended periods of time in engines at current inlet temperatures; however, before these blades are considered completely satisfactory for gas-turbine application, some means such as coatings is required to inhibit the oxidation of the blades.
Date: December 5, 1951
Creator: Stepka, Francis S. & Hickel, Robert O.
Partner: UNT Libraries Government Documents Department

Cooling of gas-turbines 7: effectiveness of air cooling of hollow turbine blades with inserts

Description: Report presenting an analytical investigation to determine primarily the reduction in cooling-air requirement and the increase in effective gas temperature for the same quantity of cooling air resulting from the use of an insert in the cooling-air passage of a hollow air-cooled turbine blade.
Date: October 20, 1947
Creator: Bressman, Joseph R. & Livingood, John N. B.
Partner: UNT Libraries Government Documents Department

Application of supersonic vortex-flow theory to the design of supersonic impulse compressor- or turbine-blade sections

Description: From Introduction: "The purpose of this paper is to present an analytical method for the design of two-dimensional related selection of a blade for particular rotor conditions may be made quickly and easily and its performance deduced from tests of representative sections in cascade."
Date: April 24, 1952
Creator: Boxer, Emanuel; Sterrett, James R. & Wlodarski, John
Partner: UNT Libraries Government Documents Department

Analytical comparison of convection-cooled turbine blade cooling-air requirements for several radial gas-temperature profiles

Description: Report presenting an analysis made to permit a comparative evaluation of the turbine rotor cooling-air requirements with convection-cooled blades for four combustor-outlet radial gas-temperature profiles: a uniform profile, a profile representable by a complete cycle of the cosine wave using cooler gas layers near the turbine casing, a profile representable by one-half cycle of the cosine wave using cooler gas layers near the stator inner ring, and an optimum profile resulting in the absolute minimum cooling-air requirements.
Date: September 7, 1955
Creator: Hubbartt, James E. & Slone, Henry O.
Partner: UNT Libraries Government Documents Department

Experimental investigation of air-cooled turbine rotor blade temperatures in a turbojet engine operating at turbine-inlet temperatures up to 2580 R and altitudes of 50,000 and 60,000 feet

Description: Report presenting temperature data for air-cooled turbine rotor blades obtained during an experimental investigation conducted in an altitude test chamber to determine some of the problems pertinent to the operation of air-cooled turbojet engines at a range of turbine-inlet temperatures. Results regarding local blade temperatures, effect of blade-inlet cooling-air temperature on average rotor blade temperature with two types of cooling, effect of cooling-air flow on average rotor blade temperature for a range of turbine-inlet temperatures, cooling-air flow requirements, and blade temperature correlation are provided.
Date: August 20, 1956
Creator: Slone, Henry O.; Cochran, Reeves P. & Dengler, Robert P.
Partner: UNT Libraries Government Documents Department

Endurance Evaluation of Sintered, Porous, Strut-Supported Turbine Blades made by Federal-Mogul-Bower-Bearings, Incorporated, under Bureau of Aeronautics Contract NOas 55-124-C

Description: Four strut-supported, transpiration-cooled turbine blades were investigated experimentally in a turbojet engine. The blade shells were fabricated by the mold-sintering method with spherical stainless-steel powder. Two blades were investigated in order to evolve suitable capping methods for the blade tip. Two other blades were used to evaluate the durability of the porous-shell material. The blades were investigated at a turbine-tip speed of 1305 feet per second, an average turbine-inlet temperature of about 1670 F, and at a porous-shell temperature limited to a maximum of approximately 1040 F.
Date: November 26, 1957
Creator: Hickel, Robert O. & Richards, Hadley T.
Partner: UNT Libraries Government Documents Department

Use of electric analog for calculation of temperature distribution of cooled turbine blades

Description: Report presenting an investigation to develop simple, inexpensive electric analogs for determining temperatures of cooled turbine blades. Analogs were made for a 13-fin shell-supported air-cooled blade, a strut-supported air-cooled blade, and a liquid-cooled blade.
Date: December 1953
Creator: Ellerbrock, Herman H., Jr.; Schum, Eugene F. & Nachtigall, Alfred J.
Partner: UNT Libraries Government Documents Department

Methods for measuring temperatures of thin-walled gas-turbine blades

Description: The accuracy and durability of two means for measuring the metal temperature of gas-turbine blades were investigated experimentally in a turbojet engine. Cemented thermocouples that could be placed in walls as thin 0.010 inch and commercial temperature-indicating paints were evaluated at turbine-inlet temperatures up to about 1650 degrees F and for centrifugal forces equivalent to about 42,000 times gravity. The cemented thermocouples operated satisfactorily. The temperature-indicating paints were neither as accurate nor as durable as the cemented thermocouples.
Date: November 2, 1956
Creator: Stepka, Francis S. & Hickel, Robert O.
Partner: UNT Libraries Government Documents Department

Theoretical and experimental analysis of the reduction of rotor blade vibration in turbomachinery through the use of modified stator vane spacing

Description: Report presenting a theoretical analysis of the dynamic gas forces produced by stationary nozzle vanes and which cause some of the resonant vibrations of the rotating blading of turbomachinery. It was found that substantial reductions of the excitation level could be obtained by altering the circumferential positions of the vanes by amounts less than plus or minus 10 percent of the normal spacing.
Date: September 1958
Creator: Kemp, Richard H.; Hirschberg, Marvin H. & Morgan, William C.
Partner: UNT Libraries Government Documents Department

Vibration of loosely mounted turbine blades during service operation of a turbojet engine with centrifugal compressor and straight-flow combustion chambers

Description: Report presenting an experimental investigation to determine the vibration characteristics of loosely mounted turbine blades during service operation of a turbojet engine. High-temperature strain gages were used to measure turbine-blade vibrations. Results regarding oscillograph records, critical speeds and frequencies, vibratory-stress levels, and effect of tightening the blade mount are provided.
Date: November 3, 1949
Creator: Morgan, W. C.; Kemp, R. H. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Vibration of turbine blades in a turbojet engine during operation

Description: Report presenting an experimental investigation to determine the vibration phenomena that occur in turbine blades of a typical jet-propulsion engine during service operation; high-temperature strain gages were used to measure the turbine-blade vibrations. Results regarding modes of vibration, centrifugal stresses, and vibration of turbine blades during operation are provided.
Date: April 22, 1948
Creator: Morgan, W. C.; Kemp, R. H. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Comparison of Calculated and Experimental Temperatures and Coolant Pressure Losses for a Cascade of Small Air-Cooled Turbine Rotor Blades

Description: From Summary: "Average spanwise blade temperatures and cooling-air pressure losses through a small (1.4-in, span, 0.7-in, chord) air-cooled turbine blade were calculated and are compared with experimental nonrotating cascade data. Two methods of calculating the blade spanwise metal temperature distributions are presented. The method which considered the effect of the length-to-diameter ratio of the coolant passage on the blade-to-coolant heat-transfer coefficient and assumed constant coolant properties based on the coolant bulk temperature gave the best agreement with experimental data."
Date: September 4, 1958
Creator: Stepka, Francis S.
Partner: UNT Libraries Government Documents Department

Method of designing corrugated surfaces having maximum cooling effectiveness within pressure-drop limitations for application to cooled turbine blades

Description: Report presenting a method using charts for the systematic determination of a corrugation geometry configuration which, for a specific application to an air-cooled turbine blade, gives the required amount of blade temperature reduction using the minimum amount of coolant flow within pressure-drop limitations. A numerical example is included to illustrate the use of the method.
Date: December 9, 1954
Creator: Slone, Henry O.; Hubbartt, James E. & Arne, Vernon L.
Partner: UNT Libraries Government Documents Department

Pressure drop in coolant passages of two air-cooled turbine-blade configurations

Description: Report presenting pressure and temperature changes in the cooling air flowing through air-cooled gas-turbine blades, which have been measured experimentally in a static cascade on a 10-tube blade for isothermal and nonisothermal flows, and on a 13-fine blade for isothermal flows. Values of pressure and temperature were obtained for a range of cooling-air flows over a range of Reynolds numbers, Mach numbers, and heat-transfer rates.
Date: June 17, 1952
Creator: Brown, W. Byron & Slone, Henry O.
Partner: UNT Libraries Government Documents Department

Comparison of theoretically and experimentally determined effects of oxide coatings supplied by fuel additives on uncooled turbine-blade temperature during transient turbojet-engine operation

Description: From Summary: "An analysis was made to permit the calculation of the effectiveness of oxide coatings in retarding the transient heat flow into turbine blades when the combustion gas temperature of a turbojet engine is suddenly changed. The analysis is checked with experimental data obtained from a turbojet engine whose blades were coated with two different coating materials (silicon dioxide and boric oxide) by adding silicone oil and tributyl borate to the engine fuel. The very thin coatings (approximately 0.001 in.) that formed on the blades produced a negligible effect on the turbine-blade transient temperature response. With the analysis discussed here, it was possible to predict the turbine rotor-blade temperature response with a maximum error of 40 F."
Date: March 30, 1953
Creator: Schafer, Louis J., Jr.; Stepka, Francis S. & Brown, W. Byron
Partner: UNT Libraries Government Documents Department

An analytical method for evaluating factors affecting application of transpiration cooling to gas turbine blades

Description: From Introduction: "A survey of some of the advantages and problems associated with transpiration cooling of gas-turbine engines is given in reference 1, and its is shown therein that high pressure gradients around the periphery of gas-turbine blades require that the blade wall permeability be varied around the blade periphery in order for uniform cooling to be obtained over the entire blade surface. This fact is verified in experimental investigations of transpiration-cooled turbine blades mounted in a static cascade (references 2 and 3) where it is shown that although transpiration cooling results in extremely effective cooling in the midchord region of the blade, there are very large variations in the chordwise temperature distribution because of improper permeability variation."
Date: September 8, 1952
Creator: Esgar, Jack B.
Partner: UNT Libraries Government Documents Department