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 Decade: 1940-1949
 Year: 1947
 Collection: National Advisory Committee for Aeronautics Collection
Investigation of the dynamic response of airplane wings to gusts

Investigation of the dynamic response of airplane wings to gusts

Date: June 1, 1947
Creator: Pierce, Harold B
Description: None
Contributing Partner: UNT Libraries Government Documents Department
An Analysis of the Full-Floating Journal Bearing

An Analysis of the Full-Floating Journal Bearing

Date: January 28, 1947
Creator: Shaw, M.C.
Description: An analysis of the operating characteristics of a full-floating bearing - a bearing in which a floating sleeve is located between the journal and bearing surfaces - is presented together with charts - from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing to verify some results of the analysis are reported. The floating sleeve can operate over a wide range of speeds for a given shaft speed, the exact value depending principally upon the ratio of clearances and upon the ratio of radii of the bearing. Lower operating temperatures at high rotative speeds are to be expected by using a full-floating bearing. This lower operating temperature would be obtained at the expense of the load-carrying capacity of the bearing if, for comparison, the clearances remain the same in both bearings. A full-floating bearing having the same load capacity as a conventional journal bearing may be designed if decreased clearances are allowable.
Contributing Partner: UNT Libraries Government Documents Department
Performance Investigation of TG-180 Combustor: I - Instrumentation, Altitude Operational Limits and Combustion Efficiency

Performance Investigation of TG-180 Combustor: I - Instrumentation, Altitude Operational Limits and Combustion Efficiency

Date: January 13, 1947
Creator: Zettle, Eugene V.
Description: A brief investigation has been made of the performance of a single combustor of the TG-180 turboJet engine to determine (a) the altitude operational limits of the engine for two fuels (AN-F-32 and AN-F-28), (b) combustion efficiencies at various simulated conditions of altitude and engine speeds, (c) combustion-outlet temperature distribution for several altitudes at constant engine speed, and (d) the combustor total pressure drop The limits with AN-83-F-32 fuel were found to be approximately 60,000 feet for an engine speed of 6000 rpm and approximately 38,000 feet for an engine speed of 1000 rpm. The results indicated that the altitude operational limits with AN-F-32 fuel are higher over the largest part of the engine-speed range than with AN-F-28 fuel, A combination efficiency of 22 percent was obtained at rated engine speed (7600 rpm) and an altitude of 20,000 feet with AN-F-32 fuel. A change in altitude from 20,000 tm 60,000 feet showed a 20-percent decrease in combustion efficiency while the engine was operating at 760G rpm whereas, at an engine speed of 4000 rpm a change of altitude from 10,000 to 40,000 feet showed a 52-percent decrease in combustion efficiency .
Contributing Partner: UNT Libraries Government Documents Department
Simulated Altitude Performance of Combustors for the 24C Jet Engine, 2, 24C-4 Combustor

Simulated Altitude Performance of Combustors for the 24C Jet Engine, 2, 24C-4 Combustor

Date: January 1, 1947
Creator: Bernardo, Everett
Description: The performance of a 24C-4 combustor was investigated with three different combustor baskets and five modifications of these baskets at conditions simulating static (zero-ram) operation of the 24C jet engine over ranges of altitude and engine speed to determine and improve the altitude operational limits of the 24C combustor. Information was also obtained regarding combustion characteristics, the fuel-flow characteristics of the fuel manifolds, and the combustor total-pressure drop. NACA modifications, which consisted of blocking rows of holes on the baskets, increased the minimum point on the altitude-operational-limit curve, which occurs at low engine speeds, for a narrow-upstream-end basket by 8000 feet (from 23, 000 to 31,000 ft_ and for a wide-upstream-end basket by 21,000 feet (from 12, 000 to 34,000 ft). These improvements were approximately maintained over the entire range of engine speeds investigated.
Contributing Partner: UNT Libraries Government Documents Department
A Theory of Unstaggered Airfoil Cascades in Compressible Flow

A Theory of Unstaggered Airfoil Cascades in Compressible Flow

Date: January 1, 1947
Creator: Spurr, Robert A.
Description: By use of the methods of thin airfoil theory, which include effects of compressibility, rela.tio^as are developed which permit the rapid determination of the pressure distribution over an unstaggered cascade of airfoils of a given profile, and the determination of the profile shape necessary to yield a given pressure distribution for small chord gap ratios, For incompressible flow the results of the theory are compared with available examples obtained by the more exact method of conformal transformation. Although the theory is developed for small chord/gap ratios, these comparisons show that it may be extended to chord/gap ratios of order unity, at least for low speed flows. Choking of cascades, a phenomenon of particular importance in compressor design, is considered.
Contributing Partner: UNT Libraries Government Documents Department
Effect of Exhaust Pressure on the Cooling Characteristics of a Liquid-Cooled Engine

Effect of Exhaust Pressure on the Cooling Characteristics of a Liquid-Cooled Engine

Date: January 20, 1947
Creator: Doyle, Ronald B.
Description: Data for a liquid-cooled engine with a displacement volume of 1710 cubic inches were analyzed to determine the effect of exhaust pressure on the engine cooling characteristics. The data covered a range of exhaust pressures from 7 to 62 inches of mercury absolute, inlet-manifold pressures from 30 to 50 inches of mercury absolute, engine speeds from 1600 to 3000 rpm, and fuel-air ratios from 0.063 to 0.100. The effect of exhaust pressure on engine cooling was satisfactorily incorporated in the NACA cooling-correlation method as a variation in effective gas temperature with exhaust pressure. Large variations of cylinder-head temperature with exhaust pressure were obtained for operation at constant charge flow. At a constant charge flow of 2 pounds per second (approximately 1000 bhp) and a fuel-air ratio of 0.085, an increase in exhaust pressure from 10 to 60 inches of mercury absolute resulted in an increase of 40 F in average cylinder-head temperature. For operation at constant engine speed and inlet-manifold pressure and variable exhaust pressure (variable charge flow), however, the effect of exhaust pressure on cylinder-head temperature is small. For example, at an inlet-manifold pressure of 40 inches of mercury absolute, an engine speed of 2400 rpm.- and a fuel-air ...
Contributing Partner: UNT Libraries Government Documents Department
Flight Investigation of the Effects of Ice on an I-16 Jet-Propulsion Engine

Flight Investigation of the Effects of Ice on an I-16 Jet-Propulsion Engine

Date: January 20, 1947
Creator: Pragliola, Philip C.
Description: A flight investigation of an I-16 jet propulsion engine installed in the waist compartment of a B-24M airplane was made to determine the effect of induction-system icing on the performance of the engine. Flights were made at inlet-air temperatures of 15 deg, 20 deg., and 25 F, an indicated airspeed of 180 miles per hour, jet-engine speeds of 13,000 and 15,000 rpm, liquid-water contents of approximately 0.3 to 0.5 gram per cubic meter, and an average water droplet size of approximately 50 microns. Under the most severe icing conditions obtained, ice formed on the screen over the front inlet to the compressor and obstructed about 70 percent of the front-inlet area. The thrust was thereby reduced 13.5 percent, the specific fuel consumption increased 17 percent, and the tail-pipe temperature increased 82 F. No icing of the rear compressor-inlet screen was encountered.
Contributing Partner: UNT Libraries Government Documents Department
A Ram-Jet Engine for Fighters

A Ram-Jet Engine for Fighters

Date: October 1, 1947
Creator: Sanger, E
Description: Simple and accurate calculations are made of the flow process in a continuous compressorless Lorin jet-propulsion unit. Experimental confirmation is given from towing tests on an airplane at flying speeds up to 200 miles per second. An analysis is made of the performance of a fighter-type airplane designed for utilization of this propulsion system.
Contributing Partner: UNT Libraries Government Documents Department
Altitude Cooling Investigation of the R-2800-21 Engine in the P-47G Airplane. IV - Engine Cooling-Air Pressure Distribution

Altitude Cooling Investigation of the R-2800-21 Engine in the P-47G Airplane. IV - Engine Cooling-Air Pressure Distribution

Date: January 7, 1947
Creator: Kaufman, Samuel J.
Description: A study of the data obtained in a flight investigation of an R-2800-21 engine in a P-47G airplane was made to determine the effect of the flight variables on the engine cooling-air pressure distribution. The investigation consisted of level flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The data showed that the average engine front pressures ranged from 0.73 to 0.82 of the impact pressure (velocity head). The average engine rear pressures ranged from 0.50 to 0.55 of the impact pressure for closed cowl flaps and from 0.10 to 0.20 for full-open cowl flaps. In general, the highest front pressures were obtained at the bottom of the engine. The rear pressures for the rear-row cylinders were .lower and the pressure drops correspondingly higher than for the front-row cylinders. The rear-pressure distribution was materially affected by cowl-flap position in that the differences between the rear pressures of the front-row and rear-row cylinders markedly increased as the cowl flaps were opened. For full-open cowl flaps, the pressure drops across the rear-row cylinders were in the order of 0.2 of the impact pressure greater than across the front-row cylinders. Propeller speed and altitude had ...
Contributing Partner: UNT Libraries Government Documents Department
Force and pressure-distribution measurements on a rectangular wing with a slotted droop nose and with either plain and split flaps in combination or a slotted flap.

Force and pressure-distribution measurements on a rectangular wing with a slotted droop nose and with either plain and split flaps in combination or a slotted flap.

Date: March 1, 1947
Creator: Lemme, H G
Description: Force measurements and pressure distribution measurements on the midsection were made on a rectangular wing with slotted droop nose and end plates, on which could be placed a choice of either a plain flap-split flap combination or a slotted flap. (author).
Contributing Partner: UNT Libraries Government Documents Department