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Knowledge Gained From Practical Experience in the Designing of Aircraft Engines

Description: The present report examines a few important points of engine design such as: in-line water cooled engines, air-cooled in-line engines, and air-cooled radial engines. Subassemblies are also discussed like cylinder types, blower driving gears, pistons, valves, bearings, and crankshafts.
Date: May 1933
Creator: Kurtz, Oskar
Partner: UNT Libraries Government Documents Department

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

Techniques for determining thrust in flight for airplanes equipped with afterburners

Description: From Summary: "An experimental technique has been developed which enables a determination of the net propulsive force acting on an afterburner-equipped airplane in flight. The thrust measurement is based on the variation of static and total pressure and stagnation temperature across the fuselage exit as determined by a swinging pitot-static pressure and temperature probe. The details are also presented for an air-cooled fixed-pressure probe for the determination of basic engine thrust."
Date: January 19, 1953
Creator: Rolls, L. Stewart; Havill, C. Dewey & Holden, George R.
Partner: UNT Libraries Government Documents Department

Initial flight investigation of a twin engine supersonic ram jet

Description: From Summary: "A flight investigation was made of a supersonic twin-ram-jet test vehicle using short-flame-length burners. The test demonstrated a maximum acceleration of 3.6g and a maximum flight Mach number of 3.02. Data were obtained over a Mach number range from about 1.9 to 3.0, an altitude range from 1,800 to 40,900 feet, and a fuel-air-ratio range from 0.012 to 0.065."
Date: September 15, 1950
Creator: Faget, Maxime A. & Dettwyler, H. Rudolph
Partner: UNT Libraries Government Documents Department

Engineering method of ram-jet thrust determination based on experimentally obtained combustor parameters

Description: From Summary: "A parameter is introduced which simplifies the accounting for pressure losses in ram-jet combustors. This parameter, called the combustor-force coefficient, relates the jet force and the total pressure at the combustion-chamber entrance. Experimental data for several different combustors are presented for evaluation and comparison."
Date: August 13, 1953
Creator: Dettwyler, H. Rudolph & Faget, Maxime A.
Partner: UNT Libraries Government Documents Department

Preliminary evaluation of the performance of a uniflow two-stroke-cycle spark-ignition engine combined with a blowdown turbine and a steady-flow turbine

Description: Report presenting calculations based on a theoretical analysis for a composite engine consisting of a uniflow two-stroke-cycle spark-ignition engine, a compressor, a blowdown turbine, and a steady-flow turbine. Operation of the engine is considered for four cases of gas mixtures and steady-flow turbine temperatures.
Date: November 25, 1947
Creator: Sather, Bernard I. & Foster, Hampton H.
Partner: UNT Libraries Government Documents Department

Fundamental flame velocities of pure hydrocarbons 2: alkadienes

Description: Data are presented for the fundamental flame velocities of 10 pure alkadienes that have isolated, conjugated, or cumulative double-bond systems. On the basis of this limited amount of data and the flame velocities previously reported, it is concluded that unsaturation changes the flame velocity in the order alkanes ? alkenes ? alkadienes with isolated double bonds ?= alkadienes with conjugated double bonds ? alkadienes with cumulative double bonds ?= alkynes. There were no significant differences in the flame velocities of cis and trans 1,3-pentadiene. The alkadienes 1,2-pentadiene and 2,3-pentadiene, with different positions of the cumulative double bond in the straight chain, have similar flame velocities. Methyl substitution in a hydrocarbon reduces the flame velocity; the extent of the reduction increases with the degree of unsaturation of the hydrocarbon.
Date: November 3, 1950
Creator: Levine, Oscar; Wong, Edgar L. & Gerstein, Melvin
Partner: UNT Libraries Government Documents Department

Fundamental flame velocities of pure hydrocarbons 1: alkanes, alkenes, alkynes benzene, and cyclohexane

Description: The flame velocities of 37 pure hydrocarbons including normal and branched alkanes, alkenes, and alkynes; as well as benzene and cyclohexane, together with the experimental technique employed are presented. The normal alkanes have about the same flame velocity from ethane through heptane with methane being about 16 percent lower. Unsaturation increases the flame velocity in the order of alkanes, alkenes, and alkynes. Branching reduces the flame velocity.
Date: September 28, 1950
Creator: Gerstein, Melvin; Levine, Oscar & Wong, Edgar L.
Partner: UNT Libraries Government Documents Department

Investigation of a supersonic-compressor rotor with turning to axial direction 1: rotor design and performance

Description: Report presenting an approximate, quasi-three-dimensional design procedure adapted to the design of high solidity, impulse-type supersonic compressors. The method is applied to a compressor rotor with a tip speed of 1600 feet per second in air, an inlet hub-tip radius ratio of 0.75, and an axial discharge relative to the rotor. Results regarding the overall performance, rotor-entrance conditions, static-pressure profiles, discharge conditions, and discharge surveys are provided.
Date: August 19, 1953
Creator: Tysl, Edward R.; Klapproth, John F. & Hartmann, Melvin J.
Partner: UNT Libraries Government Documents Department

The interdependence of various types of autoignition and knock

Description: A study of the relations existing among pin-point autoignition, homogeneous autoignition, and knock has been made by means of the NACA high-speed camera and the full-view combustion apparatus. High-speed photographic records of combustion, together with corresponding pressure-time traces, of benzene, 2,2,3-trimethylbutane, S-4, and M-4 fuels at various engine conditions have shown the engine conditions under which each of these phenomena occur and the relation of these phenomena to one another.
Date: February 10, 1947
Creator: Olsen, H. Lowell & Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Investigation of ice formation in the induction system of an aircraft engine 2: flight tests

Description: From Summary: "Flight tests were conducted on a twin-engine fighter airplane at pressure altitudes up to 10,000 feet with simulated conditions of moderate, heavy, and excessive rain to determine the increase in enthalpy of the charge air due to the turbosupercharger, to determine the rate of enthalpy increase of the charge air resulting from a sudden increase of engine power, and to compare the conditions that caused induction-system icing in flight with those that resulted in icing of the same carburetor and supercharger inlet elbow in laboratory tests."
Date: June 1946
Creator: Essex, Henry A.; Ellisman, Carl & Zlotowski, Edward D.
Partner: UNT Libraries Government Documents Department

Investigation of two-stage counterrotating compressor 2: first-rotor blade-element performance

Description: Report presenting an analysis of the blade-element performance of a highly loaded transonic rotor with double-circular-arc blades. The rotor was purposely loaded beyond the prudent level for exploratory purposes. Results regarding the radial-distribution plots, blade-element data, element blade-to-blade loss variation, and a comparison of steady-state and hot-wire measurements are provided.
Date: October 5, 1956
Creator: Wright, Linwood C. & Wilcox, Ward W.
Partner: UNT Libraries Government Documents Department

Investigation of several techniques for improving altitude starting limits of turbojet engines

Description: Report presenting a study of the altitude-starting limits of a production turbojet engine with an axial-flow compressor and a multiple through-flow combustor. The ignition limits, flame-propagation limits, and acceleration limits of the engine were improved to increase the starting limits to relatively high altitude.
Date: October 29, 1952
Creator: Armstrong, John C. & Wilsted, H. D.
Partner: UNT Libraries Government Documents Department

Investigation of spark gaps subjected to altitude and air velocity conditions

Description: Report presenting a study of the effects of air velocity on the energy and power of the spark in a constant ignition source and the duration of the spark discharge in the spark gap for various conditions of electrode spacing, electrode diameter, air temperature, and pressure. Energy and average power increased with pressure, velocity, and electrode spacing and electrode diameter and air temperature had negligible effect.
Date: November 24, 1948
Creator: Swett, Clyde C., Jr.
Partner: UNT Libraries Government Documents Department

Investigation of off-design performance of shock-in-rotor type supersonic blading

Description: An analysis of the off-design performance of shock-in rotor-type supersonic blading is presented. The over-all losses are assumed divided into two groups;normal-shock losses, and external-wave losses. Throughout the range of relative entrance Mach numbers from 1.35 to starting, the largest losses can be attributed to the normal shock. An improvement in performance would be expected with a reduction of the normal-shock losses by the introduction of external compression waves.
Date: May 7, 1951
Creator: Graham, Robert C.; Klapproth, John F. & Barina, Frank J.
Partner: UNT Libraries Government Documents Department

A Method for Prevention of Screaming in Rocket Engines

Description: From Summary: "Lateral and longitudinal combustion-pressure oscillations that occurred in screaming combustion of a 1000-pound-thrust rocket engine using white fuming nitric acid and JP-4 fuel as propellants were successfully prevented by means of longitudinal fins in the combustion chamber. Fin position was critical, and complete attenuation was achieved only when the fins were located in a zone approximately 8 to 16 inches from the injector. Fins located in other zones, that is, near the injector or far downstream from the injector, did not stop the oscillations."
Date: August 19, 1954
Creator: Male, Theodore & Kerslake, William R.
Partner: UNT Libraries Government Documents Department

Performance of five short multielement turbojet combustors for hydrogen fuel in quarter-annulus duct

Description: Report presenting an investigation of five short multielement turbojet combustors designed for use with hydrogen fuel tested in a quarter-annulus duct. One combustor had an array of U-gutter flame-holders, while the other four were manifold arrays of swirl-can combustor elements. Results regarding combustion efficiency, temperature profiles, pressure loss, durability, comparison with previous short combustors, and operation with propane fuel are provided.
Date: July 22, 1958
Creator: Jones, Robert E. & Rayle, Warren D.
Partner: UNT Libraries Government Documents Department

Oxygen boosting of an aircraft-engine cylinder in conjunction with internal coolants

Description: Report presenting an investigation to determine the possibility of attaining or approaching critical-altitude power at altitudes considerably higher than the critical as limited by the supercharger by the use of oxygen in conjunction with internal coolants.
Date: April 1944
Creator: Spencer, Robert C.; Jones, Anthony W. & Pfender, John F.
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

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

Preliminary survey of propulsion using chemical energy stored in the upper atmosphere

Description: Ram-jet cycles that use the chemical energy of dissociated oxygen for propulsion in the ionosphere are presented. After a review of the properties and compositions of the upper atmosphere, the external drag, recombination kinetics, and aerodynamic-heating problems of an orbiting ram jet are analyzed. The study indicates that the recombination ram jet might be useful for sustaining a satellite at an altitude of about 60 miles. Atmospheric composition and recombination-rate coefficients were too uncertain for more definite conclusions. The ram jet is a marginal device even in the optimistic view.
Date: May 1958
Creator: Baldwin, Lionel V. & Blackshear, Perry L.
Partner: UNT Libraries Government Documents Department