229 Matching Results

Search Results

Advanced search parameters have been applied.

Altitude-Test-Chamber Investigation of a Solar Afterburner on the 24C Engine I - Operational Characteristics and Altitude Limits

Description: An altitude-test-chamber investigation was conducted to determine the operational characteristics and altitude blow-out limits of a Solar afterburner in a 24C engine. At rated engine speed and maximum permissible turbine-discharge temperature, the altitude limit as determined by combustion blow-out occurred as a band of unstable operation of about 8000 feet altitude in width with maximum altitude limits from 32,000 feet at a Mach number of 0.3 to about 42,000 feet at a Mach number of 1.0. The maximum fuel-air ratio of the afterburner, as limited by maximum permissible turbine-discharge gas temperatures at rated engine speed, varied between 0.0295 and 0.0380 over a range of flight Mach numbers from 0.25 to 1.0 and at altitudes of 20,000 and 30,000 feet. Over this range of operating conditions, the fuel-air ratio at which lean blow-out occurred was from 10 to 19 percent below these maximum fuel-air ratios. Combustion was very smooth and uniform during operation; however, ignition of the burner was very difficult throughout the investigation. A failure of the flame holder after 12 hours and 15 minutes of afterburner operation resulted in termination of the investigation.
Date: July 6, 1948
Partner: UNT Libraries Government Documents Department

Effect of Fuel Composition, Engine Operating Variables, and Spark-Plug Type and Condition on Preignition-Limited Performance of an R-2800 Cylinder

Description: The preignition characteristics of the R-2800 cylinder, as effected by fuel consumption, engine operating variables, and spark plug type and condition, were evaluated. The effects on preignition-limited performance of various percentages of aromatics (benzene, toluene, cumene, xylene) in a base fuel of triptane were investigated. Two paraffins (triptane and S + 6.0 ml TEL/gal) and two refinery blends (28-R and 33-R) were preignition rated. The effect of changes in the following engine operating variables on preignition limit was determined: inlet-air temperature, rear spark plug gasket temperature, engine speed, spark advance, tappet clearance, and oil consumption. Preignition limits of the R-2800 cylinder using Champion C34S and C35S and AC-LS86, LS87, and LS88 spark plugs were established and the effect of spark plug deterioration was investigated.
Date: November 15, 1946
Creator: Pfender, John F.
Partner: UNT Libraries Government Documents Department

Quantitative analysis for aromatic amines in aviation fuels by ultraviolet spectrophotometry

Description: From Summary: "A method of quantitative analysis for individual aromatic amines or mixtures of aromatic amines in hydrocarbon fuel blends by spectrophotometric measurement of ultraviolet-light absorption is presented. The effect of the precision of the spectrophotometric measurements, the purity of the aromatic amine, photochemical decomposition of the amine, and the composition of the fuel on the accuracy of the analysis is discussed and the results of tests of the precision of the procedure are given."
Date: November 1945
Creator: Tischler, Adelbert O.
Partner: UNT Libraries Government Documents Department

The NACA high-speed motion-picture camera optical compensation at 40,000 photographs per second

Description: The principle of operation of the NACA high-speed camera is completely explained. This camera, operating at the rate of 40,000 photographs per second, took the photographs presented in numerous NACA reports concerning combustion, preignition, and knock in the spark-ignition engine. Many design details are presented and discussed, details of an entirely conventional nature are omitted. The inherent aberrations of the camera are discussed and partly evaluated. The focal-plane-shutter effect of the camera is explained. Photographs of the camera are presented. Some high-speed motion pictures of familiar objects -- photoflash bulb, firecrackers, camera shutter -- are reproduced as an illustration of the quality of the photographs taken by the camera.
Date: January 1, 1946
Creator: Miller, Cearcy D
Partner: UNT Libraries Government Documents Department

A relation between knock-limited or preignition-limited air-fuel ratio at lean mixtures and fuel-air ratio at rich mixtures

Description: Report presenting a derivation to show that, if the air-fuel ratio at lean mixtures is plotted against the fuel-air ratio at rich mixtures for identical values of the knock-limited indicated mean effective pressure on each side of the minimum indicated-mean-effective-pressure point, a straight line should result.
Date: November 1945
Creator: Evvard, John C.
Partner: UNT Libraries Government Documents Department

The effect of liquid and ice particles on the erosion of a supercharger-inlet cover and diffuser vanes

Description: Report discussing the results of accelerated erosion tests to determine the separate effects of the passage of fuel, water, and ice particles through a supercharger. Recommendations for preventing erosion are provided, including materials choice and joint design.
Date: June 1946
Creator: Rollin, Vern G.
Partner: UNT Libraries Government Documents Department

An evaluation of the knock-limited performance of triptane

Description: Report discussing an investigation of the knock-limited performance of triptane in F-3 and F-4 rating engines, two full-scale air-cooled aircraft cylinders, and flight tests on a full-scale multicylinder engine. Information about the lead susceptibility and effect of engine operating conditions is also provided.
Date: March 1946
Creator: Barnett, Henry C.
Partner: UNT Libraries Government Documents Department

Estimation of F-3 and F-4 knock-limited performance ratings for ternary and quaternary blends containing triptane or other high-antiknock aviation-fuel blending agents

Description: Report providing charts to assist with estimating F-3 and F-4 knock-limited performance ratings for several ternary and quaternary fuel blends. Several unusual behaviors were noted in the F-3 engines using the aromatic-paraffinic blends, so the charts for them may not be as accurate. General trends observed in different types of fuel are also described.
Date: January 1945
Creator: Barnett, Henry C.
Partner: UNT Libraries Government Documents Department

Significance of alkylate-replacement values of aviation fuel components

Description: Report discusses the significance of alkylate-replacement values and to illustrate methods of estimating these values. Equations expressing alkylate-replacement values and the estimated effect on engine performance resulting from replacement of alkylate is discussed and test data is provided in F-3 and F-4 laboratory engines. The researchers found that "alkylate-replacement value depends not only upon the rating of the fuel component that is replacing the alkylate but also upon the ratings of the alkylate and the base fuel."
Date: December 1944
Creator: Sanders, Newell D.
Partner: UNT Libraries Government Documents Department

Requirements for unit fuel-injection systems

Description: From Summary: "A unit injector was operated under various test conditions with a cam outline giving a high rate of plunger displacement. The rate of discharge of the unit injector followed the plunger displacement for the outwardly opening injection valve (open nozzle) except under conditions of high fuel pressures when the effect of fuel compressibility decreased the rate of discharge as the pressure increased. The rate of discharge for the inwardly opening injection valve (closed nozzle) did not directly follow the plunger displacement."
Date: July 1940
Creator: Marsh, Edred T.
Partner: UNT Libraries Government Documents Department

The synthesis of methylenecyclobutane, spiropentane, and 2-methyl-1-butene from pentaerythrityl tetrabromide

Description: From Summary: "Reduction of pentaerythrityl tetrabromide in ethanol with zinc in the presence of sodium carbonate and sodium iodide was found to yield methylenecyclobutane, spiropentane, and 2-methyl-l-butene. Yields were 46 percent methylenecyclobutane, 21 percent spiropentane, and 12 percent 2-methyl-l-butene. The reduction procedure described offers a method of preparing both methylenecyclobutane and spiropentane from the same reaction in yields comparable with individual methods of synthesis previously reported."
Date: February 1946
Creator: Slabey, Vernon A.
Partner: UNT Libraries Government Documents Department

Tests of an adjustable-area exhaust nozzle for jet-propulsion engines

Description: Report discussing a comparison between a centrifugal-flow-type turbojet engine with an adjustable-area exhaust nozzle and with a series of fixed-area nozzles of various throat diameters. The adjustable-area nozzle was found to be as efficient as the fixed-area nozzles in testing. Information about the corrected static thrust, fuel flow, and tail-pipe gas temperature for both types of nozzles is provided.
Date: August 16, 1945
Creator: Wilcox, E. C.
Partner: UNT Libraries Government Documents Department

An Investigation of the Icing and Heated-air De-icing Characteristics of the R-2600-13 Induction System

Description: A laboratory investigation was made on a Holley 1685-HB carburetor mounted on an R-2600-13 supercharger assembly to determine the icing characteristics and the heated-air de-icing requirements of this portion of the B-25D airplane induction system. Icing has been found to be most prevalent at relatively small throttle openings and, consequently, all runs were made at simulated 60-percent normal rated power condition. Icing characteristics were determined during a series of 15-minute runs over a range of inlet-air conditions. For the de-icing investigation severe impact ice was allowed to form in the induction system and the time required for the recovery of 95 percent of the maximum possible air flow at the original throttle setting was then determined for a range of wet-bulb temperatures. Results of these runs showed that ice on the walls of the carburetor adapter and on the rim of the impeller-shroud portion of the supercharger diffuser plate did not affect engine operation at 60-percent normal rated power. Ice that adversely affected the air flow and the fuel-air ratio was formed only on the central web of the carburetor and then only when the inlet air was saturated or contained free moisture in excess of saturation. No serious ice formations were observed at inlet-air temperatures above 66 0 F or with an inlet-air enthalpy greater than 34 Btu per pound. The maximum temperature at. which any trace of icing could be detected was 1110 F with a relative humidity of approximately 28 percent, The air-flow recovery time for emergency de-icing was 0.3 minute for.an enthalpy of 35 Btu per pound or wet-bulb temperature of 68 0 F. Further increase in enthalpy and wet-bulb temperature above these values resulted in very slight improvement in recovery time. The fuel-air ratio restored by a 5-Minute application of heated air was approximately 7 ...
Date: November 11, 1946
Creator: Chapman, Gilbert E.
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of Oil-System Performance of XR-4360-8 Engine in XTB2D-1 Airplane

Description: An investigation was conducted in the Cleveland altitude wind tunnel to determine the aerodynamic characteristics and the oil delivery critical altitude of the oil-cooler installation of an XTB2D-1 airplane. The investigation was made with the propeller removed end with the engine operating at 1800 brake horsepower, an altitude of 15,000 feet (except for tests of oil-delivery critical altitude), oil-cooler flap deflections from -20 degrees to 20 degrees and inclinations of the thrust axis of 0 degrees, 1.5 degrees, and 6 degrees. At an inclination of the thrust axis of 0 degrees and with the propeller operating, the total-pressure recovery coefficient at the face of the oil cooler varied from 0.84 to 1.10 depending on the flap deflection. With the propeller removed, the best pressure recovery at the face of the oil cooler was obtained at an inclination of the thrust axis of 1.5 degrees. Air-flow separation occurred on the inner surface of the upper lip of the oil-cooler duct inlet at an inclination of the thrust axis of 0 degrees and on the inner surface of the lower lip at 6 degrees. Static pressure coefficients over the duct lips were sufficiently low that no trouble from compressibility would be encountered in level flight. The oil-delivery critical altitude at cruising power (2230 rpm, 1675 bhp) was approximately 18,500 feet for the oil system tested.
Date: September 4, 1946
Creator: Conrad, E. William
Partner: UNT Libraries Government Documents Department

Flight Investigation of the Knock-Limited Performance of a Triptane Blend, a Toluene Blend, and 28-R Fuel in an R-1830-75 Engine

Description: Knock-limited performance data were obtained for three fuels on an R-1830-75 engine in a B-24D airplane at engine speeds of 1800, 2250, and 2600 rpm, a spark advance of 25 degrees B.T.C., and carburetor-air temperatures of 85 F for 1800 and 2250 rpm and 100 F for 2600 rpm. The test fuels were a blend of 80 percent 28-R plus 20 percent triptane (leaded to 4.5 ml TEL/gal), a blend of 80 percent 28-R plus 15 percent toluene (leaded to 4.5 ml TEL / gal), and 28-R fuel. The knock-limited manifold pressure of the toluene blend depreciated more in the lean region than the triptane blend or 28-R fuel. The knock-limited brake horsepower for the triptane blend varied from 16 to 25 percent higher than 28-R in the lean region and 18 to 30 percent higher in the rich region. The knock-limited brake horsepower of the toluene blend was approximately 15 percent higher than that of 28-R in the rich region and varied from 2 to 10 percent higher in the lean region. Knock limits of the triptane blend and 28-R fuel tested in the R-1830-75 engine agreed with limits for the same fuels determined with the R-1830-94 engine for engine speeds of 1800 and 2250 rpm.
Date: September 3, 1946
Creator: Blackman, Calvin C.
Partner: UNT Libraries Government Documents Department

The effect of engine variables on the prediction-limited performance of three fuels

Description: Report presenting preignition-limited performance data for S reference fuel, diisobutylene, and benzene with an engine-heated hot spot on a supercharged CFR engine at 11 sets of engine operating conditions. Results indicated that increases in compression ratio, spark advance, coolant temperature, or inlet-air temperature decreased the preignition-limited indicated mean effective pressure of all three fuels.
Date: September 1946
Creator: Male, Donald W.
Partner: UNT Libraries Government Documents Department

A preliminary evaluation of the explosion jet-propulsion engine

Description: Report investigating the theoretical sea-level performance of an explosion jet-propulsion engine similar to the German flying bomb to show the effects on performance of heat added and supercharging and a comparison was drawn between the performance of the explosion engine and the constant-pressure engine. The explosion engine was found to be more efficient than the constant-pressure engine at compressor pressure ratios below 3.0 when the maximum gas temperature of the constant-pressure engine is 1600 degrees Fahrenheit.
Date: August 1944
Creator: Sanders, J. C.
Partner: UNT Libraries Government Documents Department

The effect of six aromatic amines on the preignition-limited performance of 28-R aviation fuel in a CFR engine

Description: Report discussing the results of testing on the suitability of six aromatic amines as fuel additives. Antiknock effectiveness, availability, physical properties, and chemical properties for knock tests were explored. The six aromatic amines were xylidines, cumidines, N-methylxylidines, N-methylcumidines, N-methylaniline, and N-methyltoluidine in 28-R aviation fuel.
Date: May 12, 1945
Creator: Male, Donald W.
Partner: UNT Libraries Government Documents Department

Characteristics of a Hot Jet Discharged from a Jet-Propulsion Engine

Description: From Summary: "An investigation of a heated jet was conducted in conjunction with tests of an axial-flow jet-propulsion engine in the Cleveland altitude wind tunnel. Pressure and temperature surveys were made across the jet 10 and 15 feet behind the jet-nozzle outlet of the engine. Surveys were obtained at pressure altitudes of 10,000, 20,000, 30,000, and 40,000 feet with test-section velocities from 30 to 110 feet per second and test-section temperatures from 60 F to -50 F. From measurements taken throughout the operable range of engine speeds, tail-pipe outlet temperatures from 500 F to 1250 F and jet velocities from 400 to 2200 feet per second were obtained."
Date: December 27, 1946
Creator: Fleming, William A.
Partner: UNT Libraries Government Documents Department

Investigation of performance of 9-cylinder engine using large valve overlap and eclipse fuel-injection system

Description: Report presenting single-cylinder tests were made with several different engines over a period of time, which have shown that a large overlap between the time of inlet valve opening and exhaust valve closing results in a considerable increase in the maximum power obtainable from a supercharged engine and reduces cylinder temperatures.
Date: November 1941
Creator: Young, Alfred W.
Partner: UNT Libraries Government Documents Department

Effect of a low-loss air valve on performance of a 22-inch-diameter pulse-jet engine

Description: Report presenting the performance of a 22-inch-diameter pulse-jet engine using a net of low-loss modified air valves at ram pressures equivalent to simulated flight speeds. Results regarding combustion-air weight flow, flight thrust, maximum combustion-chamber pressure, specific fuel consumption, pressure cycle, and valve life are provided.
Date: June 1946
Creator: Bressman, Joseph R.
Partner: UNT Libraries Government Documents Department

Reactions with steel of compounds containing chemical groups used in lubricant additives

Description: Report presenting an investigation of the chemical reactions between steel of a type used in aircraft-engine cylinder barrels and compounds containing reactive groups commonly found in lubricant additives. The products formed by reaction at temperatures from 400 to 650 degrees F were analyzed by reflection electron diffraction. Results regarding the diffraction patterns, a description of the products found, and correlation of the results with results form other investigations are provided.
Date: February 1947
Creator: Powell, Allen S.
Partner: UNT Libraries Government Documents Department