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High-Speed Cascade Tests of the NACA 65-(12A(sub 10))10 and NACA 65-(12A(sub 2)I(sub 8b))10 Compressor Blade Sections

Description: From Summary: "Two-dimensional porous-well cascade tests of the NACA 65- (l2Al0) 10 and NACA 65-(l2A2I8b)10 blade sections were made at Mach numbers from 0.3 to choking in most cases. Data were obtained at solidities of 1.0 and 1.5 at inlet-air angles of 45 deg. and 60 deg. for both blade sections. With a solid--wall modification to the cascade tunnel, schlieren observations were made of the flow in cascade at a solidity of 1.5 and inlet-air angle of 45 deg. and at a solidity of 1.0 and inlet-air angle of 60 deg."
Date: December 21, 1955
Creator: Dunavant, James C.; Emery, James C.; Walch, Howard C. & Westphal, Willard R.
Partner: UNT Libraries Government Documents Department

Performance of an axial-flow compressor rotor designed for a pitch-section lift coefficient of 1.20

Description: Report presenting the performance of a set of axial-flow fan and compressor rotor blades with high design loading in a low-speed test blower. The efficiency curve, efficiency contours, comparison of pitch-section turning angles, and simulated blade roughness are provided.
Date: July 1947
Creator: Herrig, L. Joseph & Bogdonoff, Seymour M.
Partner: UNT Libraries Government Documents Department

Performance of axial-flow fan and compressor blades designed for high loadings

Description: Report presenting an investigation to determine the effects of loading on the performance of axial-flow fan and compressor blades in a test blower. Results regarding verification of the two-dimensional design data and effects of blade roughness are provided.
Date: February 1947
Creator: Bogdonoff, Seymour M. & Herrig, L. Joseph
Partner: UNT Libraries Government Documents Department

Systematic two-dimensional cascade tests of NACA 65-series compressor blades at low speeds

Description: A two-dimensional low-speed porous-wall cascade tunnel investigation has been conducted to establish the performance of the NACA 65-series compressor blade sections over the useful range of inlet angle, solidity, and section camber. Design points for optimum high-speed operation are presented. The loading limitation is determined for some conditions. Trends of section operating range with increasing section camber are determined for the four inlet angles tested.
Date: February 1957
Creator: Herrig, L. Joseph; Emery, James C. & Erwin, John R.
Partner: UNT Libraries Government Documents Department

Investigation of impulse-type supersonic compressor with hub-tip ratio of 0.6 and turning to axial direction 2: stage performance with three different sets of stators

Description: Report presenting an impulse-type supersonic compressor designed for turning to the axial direction that was tested in air with three different sets of stator blades at eight angle settings.
Date: August 16, 1955
Creator: Wilcox, Ward W.
Partner: UNT Libraries Government Documents Department

Empirical mode constants for calculating frequencies of axial-flow compressor blades

Description: The vibration characteristics of a group of axial-flow compressor blades of similar geometry were investigated. Empirical-mode constants were determined for the first three bending and torsional modes. A comparison of experimentally determined frequencies of a second group of blades with frequencies computed using these mode constants showed that the computed values were correct within 10 percent. The approximate limiting ratios of depth to chord and length to chord below which these constants could not be used to compute the natural frequencies were also found experimentally.
Date: April 23, 1948
Creator: Millenson, M. B. & Wilterdink, P. I.
Partner: UNT Libraries Government Documents Department

Identification of Foreign Objects Damaging Compressor Blades in Turbojet Engines

Description: "Damage to the compressor blades of turbojet engines due to ingestion of foreign objects is a growing problem, the solution of which has been made more difficult by the large percentage of damaging materials that have remained unknown. A rapid emission spectroscopic method was devised to identify the chemical composition of these foreign objects. Results on laboratory-prepared specimens and blades from damaged engines show that the method can be utilized to determine the nature of the ingested foreign objects" (p. 1).
Date: January 7, 1957
Creator: Spakowski, A. E. & Graab, J.
Partner: UNT Libraries Government Documents Department

Method for Determining the Need to Rework or Replace Compressor Rotor Blades Damaged by Foreign Objects

Description: Note presenting a method for deciding whether jet-engine compressor blades that have been nicked in service are safe from fatigue failure with continued engine operation. The method involves determining the vibratory stress distribution of the blades with damage inflicted in the laboratory. The method is judged to be a realistic criterion on inspecting damaged blades.
Date: September 1958
Creator: Kaufman, Albert
Partner: UNT Libraries Government Documents Department

Systematic two-dimensional cascade tests of NACA 65-series compressor blades at low speeds

Description: The performance of NACA 65-series compressor blade section in cascade has been investigated systematically in a low-speed cascade tunnel. Porous test-section side walls and for high-pressure-rise conditions, porous flexible end walls were employed to establish conditions closely simulating two-dimensional flow. Blade sections of design lift coefficients from 0 to 2.7 were tested over the usable angle-of-attack range for various combinations of inlet-flow angle. A sufficient number of combinations were tested to permit interpolation and extrapolation of the data to all conditions within the usual range of application. The results of this investigation indicate a continuous variation of blade-section performance as the major cascade parameters, blade camber, inlet angle, and solidity were varied over the test range. Summary curves of the results have been prepared to enable compressor designers to select the proper blade camber and angle of attack when the compressor velocity diagram and desired solidity have been determined.
Date: January 31, 1958
Creator: Emery, James C.; Herrig, L. Joseph; Erwin, John R. & Felix, A. Richard
Partner: UNT Libraries Government Documents Department

NACA 65-series compressor rotor performance with varying annulus-area ratio, solidity, blade angle, and Reynolds number and comparison with cascade results

Description: Report presenting testing of a typical axial-flow compressor rotor with NACA 65-series compressor blades at low speeds and performance measurements were made over a range of quantity flow rates at several values of annulus-area ratio, blade-setting angle, solidity, and Reynolds number to compare with porous-wall cascade results. The conclusion was reached that two-dimensional-flow porous-wall cascade results can be used to estimate rotor performance with good accuracy over a wide range of conditions.
Date: October 1957
Creator: Schulze, Wallace M.; Erwin, John R. & Ashby, George C., Jr.
Partner: UNT Libraries Government Documents Department

Method of estimating the incompressible-flow pressure distribution of compressor blade sections at design angle of attack

Description: Report presenting a method to estimate the incompressible-flow surface pressures of compressor airfoils in cascade at design angle of attack by modifying the known pressure distribution as an isolated airfoil. The interference between airfoils was found to vary in a systematic manner. Testing performed on NACA 65-series compressor blade sections appears to agree with estimated values.
Date: December 9, 1953
Creator: Erwin, John R. & Yacobi, Laura A.
Partner: UNT Libraries Government Documents Department

Effect of sweep on performance of compressor blade sections as indicated by swept-blade rotor, unswept-blade rotor, and cascade tests

Description: Report presenting an investigation to determine the induced effect of sweep on an axial-flow compressor blade. Results regarding the blade-section pressure distributions, matching pressure distributions, comparison of turning angles in compressor and cascade, corrected turning angles, and normal-force coefficients are provided.
Date: July 1957
Creator: Godwin, William R.
Partner: UNT Libraries Government Documents Department

Summary of 65-Series Compressor-Blade Low-Speed Cascade Data by Use of the Carpet-Plotting Technique

Description: Memorandum presenting the carpet-plotting technique as a more useful and concise method of summarizing the 65-series compressor-blade cascade data. Four different carpet plots are presented. A sample use of the carpet plots is also provided.
Date: November 2, 1954
Creator: Felix, A. Richard
Partner: UNT Libraries Government Documents Department

Summary of 65-Series Compressor-Blade Low-Speed Cascade Data by Use of the Carpet-Plotting Technique

Description: "The carpet-plotting technique is presented in this paper as a more useful and concise method of summarizing cascade data on the NACA 65-series compressor blades given in NACA Technical Note 3916. Carpet plots included permit the selection of the blade camber and the design angle of attack required to fulfill a design vector diagram. Other carpet plots provide means for the prediction of off-design turning angles" (p. 1).
Date: February 1957
Creator: Felix, A. Richard
Partner: UNT Libraries Government Documents Department

Experimental Investigation of a 0.4 Hub-Tip Diameter Ratio Axial-Flow Compressor Inlet Stage at Transonic Inlet Relative Mach Numbers 3: Effect of Tip Taper on Over-All and Blade-Element Performances

Description: Memorandum presenting an investigation conducted to determine the feasibility of increasing the tip-section blade-element efficiency of a transonic rotor by reducing the blade loading for a given design inlet relative Mach number. This report primarily discusses the overall and blade-element performances of the modified rotor and compares them with the performance of the original rotor.
Date: March 30, 1956
Creator: Montgomery, John C. & Glaser, Frederick
Partner: UNT Libraries Government Documents Department

Experimental Investigation of a 0.4 Hub-Tip Diameter Ratio Axial-Flow Compressor Inlet Stage at Transonic Inlet Relative Mach Numbers 4: Performance of Tapered-Tip Rotor Configuration with Reset Blade Angles

Description: Memorandum describing the blades of the tapered-tip 0.4 hub-tip diameter ratio transonic rotor, which were reset 7.5 degrees in the rotor disk and twisted from 0 degrees at the mean-radius section to 4.5 degrees at the tip to increase the specific weight flow approximately 10 percent to 36.3 pounds per second per square foot of frontal area. Results regarding the rotor overall performance, rotor flow parameters, comparison of blade-element performance and design rules, and minimum-loss and choking incidence-angle analysis at rotor hub section are provided.
Date: February 28, 1957
Creator: Montgomery, John C. & Glaser, Frederick
Partner: UNT Libraries Government Documents Department

Comparison of NACA 65-series compressor-blade pressure distributions and performance in a rotor and in cascade

Description: An investigation has been conducted to compare the performance of NACA 65-series compressor blades in two-dimensional cascade with that in an axial flow compressor. Blade pressure distributions were obtained by the use of a mercury-seal pressure-transfer device. The comparison indicated that cascade data accurately predicted the turning angle and blade pressure distribution obtained in the compressor at design conditions.
Date: March 1957
Creator: Westphal, Willard R. & Godwin, William R.
Partner: UNT Libraries Government Documents Department

A comparison of typical National Gas Turbine Establishment and NACA axial-flow compressor blade sections in cascade at low speed

Description: Report presenting comparative low-speed cascade tests of the National Gas Turbine Establishment of Great Britain axial-flow compressor blade sections at a range of air-inlet angles and a solidity of 1.0 using the porous wall technique. Results regarding a comparison of performance characteristics of the NGTE and NACA axial-flow compressor blade sections and a comparison of NGTE and NACA low-speed cascade tests of the NGTE 10C4/30C50 section are provided.
Date: March 1957
Creator: Felix, A. Richard & Emery, James C.
Partner: UNT Libraries Government Documents Department

Method of estimating the incompressible-flow pressure distribution of compressor blade sections at design angle of attack

Description: A method was devised for estimating the incompressible-flow pressure distribution over compressor blade sections at design angle of attack. The theoretical incremental velocities due to camber and thickness of the section as an isolated airfoil are assumed proportional to the average passage velocity and are modified by empirically determined interference factors. Comparisons were made between estimated and test pressure distributions of NACA 65-series sections for typical conditions. Good agreement was obtained.
Date: December 9, 1953
Creator: Erwin, John R. & Yacobi, Laura A.
Partner: UNT Libraries Government Documents Department

Experimental investigation of an axial-flow supersonic compressor having rounded leading-edge blades with an 8-percent mean thickness-chord ratio

Description: Report presenting testing of supersonic compressor blades with rounded leading edges with an 8-percent mean thickness-chord ratio and a solidity of about 2.5 were incorporated in a 16-inch-diameter rotor with and without guide vanes. Results regarding the overall performance, rotor-blade-element performance, and rotor without guide vanes are provided.
Date: December 11, 1953
Creator: Goldberg, Theodore J.; Boxer, Emanuel & Bernot, Peter T.
Partner: UNT Libraries Government Documents Department

Effect of blade-root fit and lubrication on vibration characteristics of ball-root-type axial-flow-compressor blades

Description: Report presenting the vibration characteristics of several symmetrical ball-root-type blades simulating the mass and natural frequency of axial-flow-compressor blades under various mounting conditions by subjecting them to controlled periodic excitation and centrifugal loading. Results regarding loose single ball-root mounting, loose-lubricated, single ball-root mounting, double ball-root mounting, and damping measurements are provided.
Date: June 15, 1950
Creator: Hanson, Morgan P.
Partner: UNT Libraries Government Documents Department

Diffusion factor for estimating losses and limiting blade loadings in axial-flow-compressor blade elements

Description: Report presenting a simplified limiting-blade-loading parameter for axial-flow-compressor blade elements derived from the application of a separation criterion used in two-dimensional boundary-layer theory to a typical suction-surface velocity distribution of a compressor blade element at design angle of attack. Results regarding two-dimensional cascade, compressor rotors, and compressor stators are provided.
Date: June 8, 1953
Creator: Lieblein, Seymour; Schwenk, Francis C. & Broderick, Robert L.
Partner: UNT Libraries Government Documents Department