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Wind-tunnel tests of single- and dual-rotating pusher propellers having from three to eight blades

Description: Report presenting tests of 10-foot-diameter, single- and dual-rotating pusher propellers with three to eight blades that were conducted in the 20-foot propeller research tunnel as a continuation of previous investigations of tractor propellers. The propellers were mounted at the rear end of a streamline body in spinners that covered the hubs and part of the shanks. The effects as compared to previous testing differed only in degree of effect size.
Date: February 1942
Creator: Gray, W. H.
Partner: UNT Libraries Government Documents Department

Full-scale wind-tunnel tests of a propeller with the diameter changed by cutting off the blade tips

Description: Tests were conducted in order to determine how the characteristics of a propeller are affected by cutting off the tips. The diameter of a standard 10-foot metal propeller was changed successively to 9 feet 6 inches, 9 feet 0 inches, 8 feet 6 inches, and 8 feet 0 inches. Each propeller thus formed was tested at four pitch settings using an open cockpit fuselage and a D-12 engine. A small loss in propulsive efficiency is indicated. Examples are given showing the application of the results to practical problems.
Date: December 10, 1929
Creator: Wood, Donald H.
Partner: UNT Libraries Government Documents Department

Full-scale tests of metal propellers at high tip speeds

Description: This report describes tests of 10 full-scale metal propellers of several thickness ratios at various tip speeds up to 1,350 feet per second. The results indicate no loss of efficiency up to tip speeds of approximately 1,000 feet per second. Above this tip speed the loss is at a rate of about 10 per cent per 100 feet per second increase relative to the efficiency at the lower speeds for propellers of pitch diameter ratios 0.3 to 0.4. Propellers having sections of small thickness ratio can be run at slightly higher speeds than thick ones before beginning to lose efficiency.
Date: November 5, 1930
Creator: Wood, Donald H.
Partner: UNT Libraries Government Documents Department

A method of calculating the performance of controllable propellers with sample computations

Description: This paper contains a series of calculations showing how the performance of controllable propellers may be derived from data on fixed-pitch propellers given in N.A.C.A. Technical Report No. 350, or from similar data. Sample calculations are given which compare the performance of airplanes with fixed-pitch and with controllable propellers. The gain in performance with controllable propellers is shown to be largely due to the increased power available, rather than to an increase in efficiency. Controllable propellers are of particular advantage when used with geared and with supercharged engines. A controllable propeller reduces the take-off run, increases the rate of climb and the ceiling, but does not increase the high speed, except when operating above the design altitude of the previously used fixed-pitch propeller or when that propeller was designed for other than high speed.
Date: January 1934
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department

Tests of Four Full-Scale Propellers to Determine the Effect of Trailing-Edge Extensions on Propeller Aerodynamic Characteristics

Description: Propellers with trailing-edge extensions were studied to determine aerodynamic characteristics. Trailing-edge extension increased power absorbed by propeller with little loss in efficiency. Power coefficient for maximum efficiency was greater for 20% camber type extension than for 20% straight type extension over range of advance ratio of 1.0 to 2.5 although camber type was less efficient. Efficiency was about the same for cruising and high-speed at a high power coefficient for propeller with extension.
Date: July 1945
Creator: Maynard, Julian D. & Evans, Albert J.
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics at High Speeds of Full-Scale Propellers Having Different Shank Designs

Description: From Summary: "Tests of two 10-foot-diameter two-blade propellers which differed only in shank design have been made in the Langley 16-foot high-speed tunnel. The propellers are designated by their blade design numbers, NACA 10-(5)(08)-03, which had aerodynamically efficient airfoil shank sections, and NACA l0-(5)(08)-03R which had thick cylindrical shank sections typical of conventional blades. The propellers mere tested on a 2000-horsepower dynamometer through a range of blade-angles from 20deg to 55deg at various rotational speeds and at airspeeds up to 496 miles per hour. The resultant tip speeds obtained simulate actual flight conditions, and the variation of air-stream Mach number with advance ratio is within the range of full-scale constant-speed propeller operation."
Date: February 13, 1947
Creator: Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

Turbine performance characteristics of a python turbine-propeller engine investigated in altitude wind tunnel

Description: Report presenting the performance of the turbine component of a Python turbine-propeller engine with four tail-pipe configurations determined over a range of altitudes, engine speeds, and fuel flows. Results regarding the corrected turbine speed, corrected turbine enthalpy drop, pressure ratio, and efficiency were established on a turbine-characteristic plot.
Date: May 1, 1951
Creator: Farley, John M. & Prince, William R.
Partner: UNT Libraries Government Documents Department

The negative thrust and torque of several full-scale propellers and their application to various flight problems

Description: Negative thrust and torque data for 2, 3, and 4-blade metal propellers having Clark y and R.A.F. 6 airfoil sections were obtained from tests in the NACA 20-foot tunnel. The propellers were mounted in front of a radial engine nacelle and the blade-angle settings covered in the tests ranged from l5 degrees to 90 degrees. One propeller was also tested at blade-angle settings of 0 degree, 5 degrees, and 10 degrees. A considerable portion of the report deals with the various applications of the negative thrust and torque to flight problems. A controllable propeller is shown to have a number of interesting, and perhaps valuable, uses within the negative thrust and torque range of operation. A small amount of engine-friction data is included to facilitate the application of the propeller data.
Date: 1938
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department

The effect of blade-section thickness ratio on the aerodynamic characteristics of related full-scale propellers at Mach numbers up to 0.65

Description: The results of an investigation of two 10-foot-diameter, two-blade NACA propellers are presented for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. These results are compared with those from previous investigations of five related NACA propellers in order to evaluate the effects of blade-section thickness ratios on propeller aerodynamic characteristics.
Date: April 25, 1949
Creator: Maynard, Julian D. & Steinberg, Seymour
Partner: UNT Libraries Government Documents Department

Investigation of the effect of a tip modification and thermal de-icing air flow on propeller performance

Description: Report presenting aerodynamic testing of 12.208-foot-diameter two-blade hollow steel propellers before and after alteration for thermal de-icing in the 16-foot high-speed tunnel to determine the effect of the alterations on propeller efficiency. The propeller had Clark Y blade sections tested on a 2000-horsepower dynamometer at a range of blade angles and airspeeds. Results regarding accuracy, the effect of the alteration, effect of internal air flow, effect of compressibility, and coefficient of mass flow of de-icing air are provided.
Date: July 1946
Creator: Corson, Blake W., Jr. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

The Langley 2,000-horsepower propeller dynamometer and tests at high speed of an NACA 10-(3)(08)-03 two-blade propeller

Description: This paper contains a detailed description of a 2,000-horsepower propeller dynamometer used to make wind-tunnel tests of a two-blade NACA 10-(3)(08)-03 propeller for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests and comparisons with results obtained from a theoretical analysis and from previous tests made in other wind tunnels are presented.
Date: December 1952
Creator: Corson, Blake W., Jr. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

The NACA 2000-horsepower propeller dynamometer and tests at high speed of an NACA 10-(3)(08)-03 two-blade propeller

Description: This paper contains a detailed description of a 2,000-horsepower propeller dynamometer used to make wind-tunnel tests of a two-blade NACA 10-(3)(08)-03 propeller for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests and comparisons with results obtained from a theoretical analysis and from previous tests made in other wind tunnels are presented.
Date: July 20, 1948
Creator: Corson, Blake W., Jr. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

Wind-tunnel vibration tests of dual-rotating propellers

Description: Report presenting vibration tests of six- and eight-blade tractor and seven- and eight-blade pusher dual-rotating propellers conducted in the 16-foot high-speed tunnel to determine the severity of vibrations excited by blade passages. Measurements of vibratory stresses were made for engine-speed ranges at low, intermediate, and high engine powers. Few vibrations caused by blade passages were detected, and those vibrations were not serious.
Date: September 1943
Creator: Miller, Mason F.
Partner: UNT Libraries Government Documents Department

Considerations of wake-excited vibratory stress in a pusher propeller

Description: Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited vibratory stress in a propeller increases with the drag of the body producing the wake.
Date: February 1944
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests of single- and dual-rotating tractor propellers of large blade width

Description: Report presenting tests of 10-foot diameter, single- and dual-rotating tractor propellers with two to eight blades conducted in the 20-foot propeller-research tunnel. The blades were 50 percent wider than those used in previous investigations. Results regarding the effect of dual rotation and effect of solidity are provided.
Date: September 1942
Creator: Biermann, David; Gray, W. H. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department

On the elementary relation between pitch, slip, and propulsive efficiency

Description: The author examines the current theory on the importance of reducing slip in airplane propellers. The author feels an exaggerated importance is attached to this supposition and feels that the increase in friction by an increase in propeller area or number of revolutions can't be discounted.
Date: 1920
Creator: Froude, W.
Partner: UNT Libraries Government Documents Department

Preliminary investigation of the characteristics of a two dimensional wing and propeller with the propeller plane of rotation in the wing-chord plane

Description: Report detailing an investigation of the aerodynamic characteristics of a wing-propeller combination with the propeller rotating in the wing-chord plane of a two-dimensional wing. Total static lift was measured with and without the wing for a 3-foot-diameter propeller, while the effects of a ground plane on the static lift of the wing-propeller combination were measured with a 2-foot-diameter propeller. Results regarding static testing, forward speed tests, and propeller loads are provided.
Date: August 1, 1957
Creator: Hickey, David H.
Partner: UNT Libraries Government Documents Department

The effect of compressibility on eight full-scale propellers operating in the take-off and climbing range

Description: Tests were made of eight full-scale propellers of different shape at various tip speeds up to about 1,000 feet per second. The range of blade-angle settings investigated was from 10 degrees to 30 degrees at the 0.75 radius. The results indicate that a loss in propulsive efficiency occurred at tip speeds from 0.5 to 0.7 the velocity of sound for the take-off and climbing conditions. As the tip speed increased beyond these critical values, the loss rapidly increased and amounted, in some instances, to more than 20 percent of the thrust power for tip-speed values of 0.8 the speed of sound. In general, as the blade-angle setting was increased, the loss started to occur at lower tip speeds. The maximum loss for a given tip speed occurred at a blade-angle setting of about 20 degrees for the take-off and 25 degrees for the climbing condition. A simplified method for correcting propellers for the effect of compressibility is given in an appendix.
Date: January 1, 1938
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department

Critical speeds and profile drag of the inboard sections of a conventional propeller

Description: Report presenting the section critical speeds and profile drags of the shank and hub sections of a propeller used on a current liquid-cooled-engine pursuit type of airplane. Results indicated that serious adverse compressibility effects can be expected at speeds of about 400 miles per hour. Suitable fairings for shank and hub sections were found to be necessary for maximum propulsive efficiency.
Date: September 1941
Creator: Luoma, Arvo A.
Partner: UNT Libraries Government Documents Department

Aerodynamic investigation of a four-blade propeller operating through an angle-of-attack range from 0 to 180 degrees

Description: Report presenting an investigation of the aerodynamic characteristics of a four-blade rigid model propeller in the full-scale tunnel for a range of angles of attack, blade angles, and advance ratio. It included a preliminary explanation of vertical descent and a comparison with theory. Results regarding the static thrust and forward flight are provided.
Date: June 1954
Creator: McLemore, H. Clyde & Cannon, Michael D.
Partner: UNT Libraries Government Documents Department

The aerodynamic characteristics of full-scale propellers having 2, 3, and 4 blades of Clark y and R.A.F. 6 airfoil sections

Description: Aerodynamic tests were made of seven full-scale 10-foot-diameter propellers of recent design comprising three groups. The first group was composed of three propellers having Clark y airfoil sections and the second group was composed of three propellers having R.A.F. 6 airfoil sections, the propellers of each group having 2, 3, and 4 blades. The third group was composed of two propellers, the 2-blade propeller taken from the second group and another propeller having the same airfoil section and number of blades but with the width and thickness 50 percent greater. The tests of these propellers reveal the effect of changes in solidity resulting either from increasing the number of blades or from increasing the blade width propeller design charts and methods of computing propeller thrust are included.
Date: 1938
Creator: Hartman, Edwin P. & Biermann, David
Partner: UNT Libraries Government Documents Department

Comparison of full-scale propellers having R.A.F.-6 and Clark Y airfoil sections

Description: In this report the efficiencies of two series of propellers having two types of blade sections are compared. Six full-scale propellers were used, three having R. A. F.-6 and three Clark Y airfoil sections with thickness/chord ratios of 0.06, 0.08, and 0.10. The propellers were tested at five pitch setting, which covered the range ordinarily used in practice. The propellers having the Clark Y sections gave the highest peak efficiency at the low pitch settings. At the high pitch settings, the propellers with R. A. F.-6 sections gave about the same maximum efficiency as the Clark Y propellers and were more efficient for the conditions of climb and take-off.
Date: October 8, 1930
Creator: Freeman, Hugh B.
Partner: UNT Libraries Government Documents Department

Static tests of a shrouded and an unshrouded propeller

Description: Report presenting outdoor static testing made on two high-solidity propellers of different design, one shrouded and the other unshrouded. Three shrouds were tested to determine the effects of shroud length and exit area. Results regarding the action of shroud, results and comparison of propellers, and comparison with theory are provided.
Date: February 9, 1948
Creator: Platt, Robert J., Jr.
Partner: UNT Libraries Government Documents Department

The Characteristics of Two Model Six-Blade Counterrotating Pusher Propellers of Conventional and Improved Aerodynamic Design

Description: Two airfoil plans were used for propeller blades. One is modified Clark Y section designed for structural reliability and the second an NACA 16 airfoil section designed to produce minimum aerodynamic losses. At low air speeds, the propeller designed for aerodynamic effects showed a gain of from 1.5 to 4.0 percent in propulsive efficiency over the conventional type depending on the pitch. Because of the numerous variables involved, the effect of each one on the aerodynamic characteristics of the propellers could not be isolated.
Date: June 1942
Creator: McHugh, James G. & Pepper, Edward
Partner: UNT Libraries Government Documents Department