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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

Evaluation of effects of random permeability variations on transpiration-cooled surfaces

Description: Report presenting an analytical investigation to evaluate the effects of permeability variations on surface temperatures and coolant flows for ranges of temperature and Reynolds number that are of particular interest for gas-turbine blades. Results regarding small-orifice calibrations, effect of orifices in series with porous surfaces on permeability correlation, effect of permeability variations on coolant-flow rates and porous-wall temperatures, evaluation of the experimental porous blade, and design features for transpiration-cooled turbine blades are provided.
Date: November 30, 1953
Creator: Esgar, Jack B. & Richards, Hadley T.
Partner: UNT Libraries Government Documents Department

Experimental Permeability Measurements on a Strut-Supported Transpiration-Cooled Turbine Blade with Stainless-Steel Shell made by the Federal-Mogul Corporation under Bureau of Aeronautics Contract N0as 51613-C

Description: A turbine blade with a porous stainless-steel shell sintered to a supporting steel strut has been fabricated for tests at the NACA by Federal-Mogul Corporation under contract from the Bureau of Aeronautics, Department of the Navy. The apparent permeability of this blade, on the average, more nearly approaches the values specified by the NAGA than did two strut-supported bronze blades in a previous investigation. Random variations of permeability in the present blade are substantialy greater than those of the bronze blades, but projected improvements in certain phases of the fabrication process are expected to reduce these variations.
Date: April 30, 1954
Creator: Richards, Hadley T.
Partner: UNT Libraries Government Documents Department

Vibrational modes of several hollow turbine blades and of solid turbine blade of similar aerodynamic design

Description: Experimental study to determine the vibrational modes of several hollow turbine blades and a solid turbine blade of similar aerodynamic design. Results regarding the significance of nodal patterns, vibrational modes of six blade types, and the probability of excitation in some of the blades are provided.
Date: October 3, 1949
Creator: Kemp, R. H. & Shifman, J.
Partner: UNT Libraries Government Documents Department

Determination and use of the local recovery factor for calculating the effectiveness gas temperature for turbine blades

Description: In an in experimental investigation of local recovery factors for a blade having a pressure distribution similar to that of a typical reaction-type turbine blade, it a was found that the recovery factors were essentially independent of Mach number, Reynolds number, pressure gradient, and position on the blade surface except for regions where the boundary layer was probably in the transition range from laminar to turbulent. The recommended value of local subsonic recovery factor for use in calculating the effective gas temperature for gas turbine blades was 0.89.
Date: September 24, 1951
Creator: Esgar, Jack B. & Lea, Alfred L.
Partner: UNT Libraries Government Documents Department

Analytical investigation of effect of water-cooled turbine blades on performance of turbine-propeller power plants

Description: From Introduction: "Finally the work of the report is applied exclusively to consideration of the turbine-propeller power plant because previous performance analyses of the various gas-turbine propulsion systems combine with recent improvements in propeller design indicate that it is this combination which, will give the best over-all performance in the speed ranges considered."
Date: August 16, 1948
Creator: Bowman, William D
Partner: UNT Libraries Government Documents Department

Analytical investigation of distribution of centrifugal stresses and their relation to limiting operating temperatures in gas-turbine blades

Description: From Introduction: "Analyses that provide a basis for comparing the centrifugal-stress distributions inherent in jet-engine turbine blades of several designs currently in use were therefore made and are presented."
Date: April 12, 1948
Creator: Kemp, Richard H. & Morgan, William C.
Partner: UNT Libraries Government Documents Department

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

Description: From Summary: "Procedures for applying these analytical methods to experimentally measured blade-metal temperatures are presented. Data are presented for the leading and trailing edge of a symmetrical water-cooled blade to illustrate the validity of the methods for those portions of the blade. In addition to the application to turbine blades, the methods can be applied to any heat-transfer apparatus having a profile that can be approximated by the shape discussed."
Date: April 10, 1950
Creator: Brown, W. Byron & Esgar, Jack B.
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