3,382 Matching Results

Search Results

Advanced search parameters have been applied.

Design and Experimental Investigation of Light-Weight Bases for Air-Cooled Turbine Rotor Blades

Description: Memorandum presenting an investigation of the problem of air-cooled turbine rotor-blade weight reduction for aircraft gas turbines as part of the NACA turbine-cooling research program. A bulb-root-type blade-base design was achieved which utilized forming and brazing techniques in its manufacture and was combined with an axial-flow turbojet engine aerodynamic profile. Results regarding the sheet-metal bulb-root-type air-cooled base designs, air-cooled pinned-type base design, and some weight reduction considerations are provided.
Date: July 2, 1954
Creator: Freche, John C. & McKinnon, Roy A.
Partner: UNT Libraries Government Documents Department

Performance evaluation of reduced-chord rotor blading as applied to J73 two-stage turbine 5: effect of inlet pressure on over-all performance at design speed and inlet temperature of 700 degrees R

Description: Report presenting an investigation of a reduced-chord multistage turbine at design speed and various turbine-inlet pressures from 12 to 40 inches of mercury absolute. At each inlet pressure, the turbine was operated over a range of overall turbine total-pressure ratios; turbine-inlet temperature was maintained at 700 degrees R. The results indicated that no appreciable effect on turbine overall performance was observed over the range of turbine-inlet total pressures investigated.
Date: July 5, 1957
Creator: Schum, Harold J.
Partner: UNT Libraries Government Documents Department

The Efficiency of Combustion Turbines With Constant-Pressure Combustion

Description: "Of the two fundamental cycles employed in combustion turbines, namely, the explosion (or constant-volume) cycle and the constant-pressure cycle, the latter is considered more in detail and its efficiency is derived with the aid of the cycle diagrams for the several cases with adiabatic and isothermal compression and expansion strokes and with and without utilization of the exhaust heat. Account is also taken of the separate efficiencies of the turbine and compressor and of the pressure losses and heat transfer in the piping. The results show that without the utilization of the exhaust heat the efficiencies for the two cases of adiabatic and isothermal compression is offset by the increase in the heat supplied" (p. 1).
Date: April 1941
Creator: Piening, Werner
Partner: UNT Libraries Government Documents Department

Experimental Investigation of a 7-Inch-Tip-Diameter Transonic Turbine

Description: Memorandum presenting the overall performance results obtained for a 7-inch transonic turbine and a comparison with the results of a 14-inch turbine of geometrically similar design that had been previously investigated. The peak efficiency obtained with the turbine was 0.85, which was 2 points lower than that obtained previously with the 14-inch turbine.
Date: January 16, 1958
Creator: Whitney, Warren J. & Wintucky, William T.
Partner: UNT Libraries Government Documents Department

Design and Experimental Investigation of a Single-Stage Turbine With a Rotor Entering Relative Mach Number of 2

Description: Memorandum presenting a design and experimental investigation of a single-stage supersonic turbine. The turbine was designed for a rotor entering relative Mach number of 2. Results regarding the overall turbine performance, outer-wall static-pressure variation, momentum-loss considerations, effect of rotor modifications, and supersonic starting are provided.
Date: September 15, 1958
Creator: Moffitt, Thomas P.
Partner: UNT Libraries Government Documents Department

Investigation of turbines suitable for use in a turbojet engine with high compressor pressure ratio and low compressor-tip speed 6: experimental performance of two-stage turbine

Description: The brake internal efficiency of the highly loaded two-stage turbine was 0.79 equivalent design work and speed. The maximum brake internal efficiency was 0.84. A radial survey revealed these major defects: (1) the first-rotor throat area was too large, and a large area of underturned flow existed near the tip;(2) considerable underturning existed at the second-stator outlet; and (3) tangential components of velocity at the turbine outlet amounted to 2.5 points in turbine efficiency.
Date: August 20, 1956
Creator: Davison, Elmer H.; Schum, Harold J. & Petrash, Donald A.
Partner: UNT Libraries Government Documents Department

Mechanical design analysis of several noncritical air-cooled turbine disks and a corrugated-insert air-cooled turbine rotor blade

Description: Report presenting a series of turbine wheel designs made for a turbojet engine with an axial-flow compressor. The designs were made to determine the influence of air-cooling on overall engine design, weight, critical-material content, and complexity and to assist with construction of research model full-scale turbines.
Date: July 22, 1953
Creator: Moseson, Merland L.; Krasner, Morton H. & Ziemer, Robert R.
Partner: UNT Libraries Government Documents Department

One-Dimensional Analysis of Choked-Flow Turbines

Description: "Turbines for most applications requiring high work output per stage have one or more blade rows which are choked. This analysis indicated that the area ratios and equivalent blade speed are the controlling factors in the design and operation of such turbines. Six criteria are stated that will aid in establishing from test data of multistage turbines which blade rows are choked and which are not" (p. 1).
Date: 1953
Creator: English, Robert E. & Cavicchi, Richard H.
Partner: UNT Libraries Government Documents Department

Performance Evaluation of Reduced-Chord Rotor Blading as Applied to J73 Two-Stage Turbine

Description: "The multistage turbine from the J73 turbojet engine has previously been investigated with standard and with reduced-chord rotor blading in order to determine the individual performance characteristics of each configuration over a range of over-all pressure ratio and speed. Because both turbine configurations exhibited peak efficiencies of over 90 percent, and because both units had relatively wide efficient operating ranges, it was considered of interest to determine the performance of the first stage of the turbine as a separate component. Accordingly, the standard-bladed multistage turbine was modified by removing the second-stage rotor disk and stator and altering the flow passage so that the first stage of the unit could be operated independently" (p. 1).
Date: July 11, 1957
Creator: Schum, Harold J.
Partner: UNT Libraries Government Documents Department

Performance Evaluation of Reduced-Chord Rotor Blading as Applied to J73 Two-Stage Turbine 6: Stage Performance With Standard Rotor Blading at Inlet Conditions of 35 Inches of Mercury Absolute and 700 Degrees R

Description: Report presenting an evaluation of the stage performance of the J73 turbine on the basis of previous performance investigations of the first stages alone and of the two-stage turbines with standard and with reduced-chord rotor blading for a range of rotational speeds and pressure ratios. The results demonstrated that both of the two-stage turbines and first-stage turbines had comparable performance.
Date: July 11, 1957
Creator: Davison, Elmer H. & Schum, Harold J.
Partner: UNT Libraries Government Documents Department

Performance of 19XB-2A Gas Turbine 1 - Effect of Pressure Ratio and Inlet Pressure on Turbine Performance for an Inlet Temperature of 800 Degrees R

Description: "An investigation of the 19XB-2A gas turbine is being conducted at the Cleveland laboratory to determine the effect on turbine performance of various inlet pressures, inlet temperatures, pressure ratios, and wheel speeds. The engine of which this turbine is a component is designed to operate at an air flow of 30 pounds per second at a compressor rotor speed of 17,000 rpm at sea-level conditions. At these conditions the total-pressure ratio is 2.08 across the turbine and the turbine inlet total temperature is 2000 degrees R" (p. 1).
Date: December 26, 1946
Creator: Kohl, Robert C. & Larkin, Robert G.
Partner: UNT Libraries Government Documents Department

Investigation of a Transonic Turbine Designed for a Maximum Rotor-Blade Suction-Surface Relative Mach Number of 1.57

Description: "A transonic turbine designed for a maximum blade-surface relative Mach number of 1.57 was investigated experimentally. The performance of the turbine is compared with that of three other transonic turbines that were previously investigated" (p. 1).
Date: October 11, 1954
Creator: Whitney, Warren J.; Wong, Robert Y. & Monroe, Daniel E.
Partner: UNT Libraries Government Documents Department

Investigation of First Stage of Two-Stage Turbine Designed for Free-Vortex Flow

Description: Note presenting an experimental investigation of the first stage of a two-stage turbine designed for free-vortex flow. The results of the investigation showed that highest adiabatic efficiency was attained when the turbine was operating near the design total-pressure ratio. Results regarding power and efficiency, weight rate of gas flow through the turbine, weight-flow distribution at stator-cascade outlets, stator and rotor flow angles at mean radii, radial distribution of flow angle, radial distribution of the rotor-outlet flow angle, radial distribution of the total pressures at the stator-cascade outlet, and radial distribution of rotor-outlet pressure are provided.
Date: June 1950
Creator: Englert, G. W. & Ross, A. O.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Stage Performance of J71 Three-Stage Turbine

Description: "An experimental investigation of the stage performance of the J71 three-stage turbine at design speed and pressure ratio was conducted as part of a program involving research on the design and operational characteristics of high-work-output multistage axial-flow turbines. The investigation indicated that the over-all work output of the turbine based on temperature measurements at design speed and pressure ratio was 95 percent of the design value, with the greatest loss in work output and efficiency occurring in the first stage. Choking in the second-stage stator over most of the pressure ratios investigated prevented the attainment of design first-stage work output and also prevented any increase in work output of the first stage with increasing over-all pressure ratio at design speed" (p. 1).
Date: December 20, 1954
Creator: Forrette, Robert E.
Partner: UNT Libraries Government Documents Department

Construction and Use of Charts in Design Studies of Gas Turbines

Description: "A method is presented for the computation and graphic representation of a series of possible turbine designs for any specific application. The use of a preliminary design chart is suggested for determining the number of stages and the effects of exit whirl and annular-area divergence on possible configurations. A specific design chart can then be made to aid in the study of the relations between turbine radius ratio, diameter, and significant design parameters such as Mach numbers, turning angles, and blade root stresses" (p. 1).
Date: July 1951
Creator: Alpert, Sumner & Litrenta, Rose M.
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines, 3, Analysis of Rotor and Blade Temperatures in Liquid-Cooled Gas Turbines

Description: A theoretical analysis of the radial temperature distribution through the rotor and constant cross sectional area blades near the coolant passages of liquid cooled gas turbines was made. The analysis was applied to obtain the rotor and blade temperatures of a specific turbine using a gas flow of 55 pounds per second, a coolant flow of 6.42 pounds per second, and an average coolant temperature of 200 degrees F. The effect of using kerosene, water, and ethylene glycol was determined. The effect of varying blade length and coolant passage lengths with water as the coolant was also determined. The effective gas temperature was varied from 2000 degrees to 5000 degrees F in each investigation.
Date: February 11, 1947
Creator: Brown, W. Byron & Livingood, John N. B.
Partner: UNT Libraries Government Documents Department

A general representation for axial-flow fans and turbines

Description: From Summary: "A general representation of fan and turbine arrangements on a single classification chart is presented which is made possible by a particular definition of the stage of an axial-flow fan or turbine. Several unconventional fan and turbine arrangements are indicated and the applications of these arrangements are discussed."
Date: June 1945
Creator: Perl, W. & Tucker, M.
Partner: UNT Libraries Government Documents Department

Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Description: "Hot-air engines with dynamic compressors and turbines offer new prospects of success through utilization of units of high efficiencies and through the employment of modern materials of great strength at high temperature. Particular consideration is given to an aerodynamic prime mover operating on a closed circuit and heated externally. Increase of the pressure level of the circulating air permits a great increase of limit load of the unit. This also affords a possibility of regulation for which the internal efficiency of the unit changes but slightly. The effect of pressure and temperature losses is investigated" (p. 1).
Date: November 1942
Creator: Ackeret, J. & Keller, D. C.
Partner: UNT Libraries Government Documents Department

Flight Performance of a Jet Power Plant, 3, operating characteristics of a jet power plant as a function of altitude

Description: The performance of a jet power plant consisting of a compressor and a turbine is determined by the characteristic curves of these component parts and is controllable by the characteristics of the compressor and the turbine in relation to each other. The normal. output, overload, and throttled load of the Jet power plant are obtained on the basis of assumed straight-line characteristics.
Date: May 1951
Creator: Weinig, F.
Partner: UNT Libraries Government Documents Department

Performance evaluation of reduced-chord rotor blading as applied to J73 two-stage turbine 1: over-all performance with standard rotor blading at inlet conditions of 35 inches of mercury absolute and 700 degrees R

Description: Report presenting an investigation conducted to determine the overall performance of the J73 two-stage turbine with a standard rotor-blade configuration. The turbine operated with a maximum brake internal efficiency between 0.91 and 0.92 at an overall pressure ratio of about 3.4 and 120 percent equivalent design rotor speed. Results regarding the overall performance, variation of equivalent weight flow with overall pressure ratio, and effect of limiting blade loading are provided.
Date: July 11, 1957
Creator: Berkey, William E.; Rebeske, John J., Jr. & Forrette, Robert E.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of an 0.8 Hub-Tip Radius-Ratio, Nontwisted-Rotor-Blade Turbine

Description: "An experimental investigation of a 0.8 hub-tip radius ratio, nontwisted-rotor-blade turbine designed for a stagnation-pressure ratio of 2.5 and an equivalent mean blade speed of 643 feet per second was made in a cold-air turbine with (a) nontwisted stator blades, and (b) twisted stator blades designed to maintain zero rotor-inlet incidence angles. Turbine efficiencies of the order of 0.85 at the design point were obtained with a nontwisted-rotor-blade turbine with a hub-tip radius ratio of 0.80. The turbine with the twisted stator blades gave higher efficiencies at the design point (of the order of 1.5 percentage points) than the turbine with the nontwisted stator blades" (p. 1).
Date: December 12, 1951
Creator: Silvern, David H. & Slivka, William R.
Partner: UNT Libraries Government Documents Department

Investigation of a Related Series of Turbine-Blade Profiles in Cascade

Description: From Summary: "An application of airfoil design methods was used to design series of related turbine-blade profiles to satisfy the conditions of inlet flow angle and turning angle encountered in the usual range of turbine operation. A series of blade profiles applicable to most turbine blading requirements and a secondary series with particular reference to impulse conditions were designed. Five blade sections from these series ranging in mean-line turning angles from 63 deg. to 120 deg. were tested in low-speed cascade tunnels."
Date: December 7, 1953
Creator: Dunavant, James C. & Erwin, John R.
Partner: UNT Libraries Government Documents Department