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  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Research Memorandums
 Collection: Technical Report Archive and Image Library
Altitude-Wind-Tunnel Investigation of Oil-System Performance of XR-4360-8 Engine in XTB2D-1 Airplane

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

Date: September 4, 1946
Creator: Conrad, E. William
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 ...
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Analytical investigation of the use of regeneration in compressor-turbine-propeller systems

Analytical investigation of the use of regeneration in compressor-turbine-propeller systems

Date: September 9, 1946
Creator: Wood, George P
Description: The use of regenerative heat exchangers in compressor-turbine-propeller aircraft power plants has been investigated.
Contributing Partner: UNT Libraries Government Documents Department
Investigation of Three Design Modifications of the NACA Injection Impeller in an R-3350 Engine

Investigation of Three Design Modifications of the NACA Injection Impeller in an R-3350 Engine

Date: September 9, 1946
Creator: Hickel, Robert O.
Description: An investigation was conducted to determine the effects of three design modifications of the original NACA injection impeller on the performance of an R-3350 engine. Different methods of injecting the fuel into the impeller air stream were studied and evaluated from the individual cylinder fuel-air ratios and the resulting cylinder temperatures. Each impeller was tested for a range of engine powers normally used in flight operation. The relatively simple design of the original injection impeller produced approximately the same mixture- and temperature-distribution characteristics as the modified impellers of more complex design. None of the modifications appreciably affected the manifold pressure, the combustion-air flow, nor the throttle angle required to maintain a given engine power,.
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Altitude-wind-tunnel investigations of thrust augmentation of a turbojet engine performance with tail-pipe burning

Altitude-wind-tunnel investigations of thrust augmentation of a turbojet engine performance with tail-pipe burning

Date: September 25, 1946
Creator: Fleming, W A
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Tests to Determine Aileron Characteristics of the McDonnell XFD-1 Airplane, TED No. NACA 23102

Wind-Tunnel Tests to Determine Aileron Characteristics of the McDonnell XFD-1 Airplane, TED No. NACA 23102

Date: September 26, 1946
Creator: Yates, Campbell C.
Description: Tests were performed on a partial span of the wing of a McDonnell XFD-1 airplane to determine a combination of sealed internal balance and spring-tab stiffness for the aileron that would give satisfactory stick-force characteristics for the airplane. Two sealed internal balances were tested in combination with spring tabs of various stiffnesses. One of the combinations was tested at several speeds to determine the variation of stick force with speed. Estimates, based on the results of the tests, indicate that for this airplane any reduction of stick force by use of the spring tab reduces the helix angle pb/2V below the required value of 0.09. The estimates show that, of the configurations tested, the most satisfactory combination for obtaining a stick force of 30 pounds at 300 miles per hour indicated airspeed is a 0.48-chord internal balance in combination with a spring-tab stiffness of 500 pounds per inch. With this combination, a wing-tip helix angle of 0.078 is estimated. Stick-force curves for all configurations show a rapid increase in stick force above approximately 20 deg. total aileron deflection.
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Free-Spinning-Tunnel Tests of a 1/18-Scale Model of the Fairchild XNQ-1 Airplane, TED No. NACA 2398

Free-Spinning-Tunnel Tests of a 1/18-Scale Model of the Fairchild XNQ-1 Airplane, TED No. NACA 2398

Date: September 30, 1946
Creator: Daughtridge, Lee T., Jr.
Description: Spin tests have been performed in the Langley 20-foot free-spinning tunnel on a 1/18-scale model of the Fairchild XNQ-1 airplane. The spin and recovery characteristics of the model were determined for the normal gross-weight loading and for two variations from this loading - center of gravity moved rearward and relative mass distribution increased along the fuselage. These tests were performed for two vertical-tail plan forms. The investigation also included simulated pilot-escape tests and rudder-force tests. The recovery characteristics of the model were satisfactory for all conditions tested by full reversal of the rudder and by simultaneous neutralization of the rudder and elevator. It was indicated that if necessary to escape from the spinning airplane, the pilot should jump from the outboard side of the fuselage and as far rearward as possible. Aa determined from spin model tests, the rudder pedal force required to reverse the rudder for recovery from the spin will be light.
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Flight Investigation of Effect of Various Vertical-Tail Modifications on the Directional Stability and Control Characteristics of the P-63A-1 Airplane (AAF No. 42-68889)

Flight Investigation of Effect of Various Vertical-Tail Modifications on the Directional Stability and Control Characteristics of the P-63A-1 Airplane (AAF No. 42-68889)

Date: October 7, 1946
Creator: Johnson, Harold I.
Description: Because the results of preliminary flight tests had indicated. the P-63A-1 airplane possessed insufficient directional stability, the NACA and the manufacturer (Bell Aircraft Corporation) suggested three vertical-tail modifications to remedy the deficiencies in the directional characteristics. These modifications included an enlarged vertical tail formed by adding a tip extension to the original vertical tail, a large sharp-edge ventral fin, and a small dorsal fin. The enlarged vertical tail involved only a slight increase in total vertical-tail area from 23.73 to 26.58 square feet but a relatively much larger increase in geometric aspect ratio from 1.24 to 1.73 based on height and area above the horizontal tail. At the request of the Air Material Command, Army Air Forces, flight tests were made to determine the effect of these modifications and of some combinations of these modifications on the directional stability and control characteristics of the airplane, In all, six different vertical-tail. configurations were investigated to determine the lateral and directional oscillation characteristics of the airplane, the sideslip characteristics, the yaw due to ailerons in rudder-fixed rolls from turns and pull-outs, the trim changes due to speed changes; and the trim changes due to power changes. Results of the tests showed that ...
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Flight and test-stand investigation of high-performance fuels in Pratt & Whitney R-1830-94 engines IV : comparison of cooling characteristics of flight and test-stand engines

Flight and test-stand investigation of high-performance fuels in Pratt & Whitney R-1830-94 engines IV : comparison of cooling characteristics of flight and test-stand engines

Date: October 8, 1946
Creator: Werner, Milton
Description: The cooling characteristics of three R-1830-94 engines, two of which were mounted in a test stand and the other in a B-24D airplane, were investigated and the results were compared. The flight tests were made at a pressure altitude of 7000 feet; the test-stand runs were made at ground-level atmospheric conditions. Three cooling runs were made for each engine: variable cooling-air pressure drop, variable carburetor-air flow, and variable fuel-air ratio. Actual cylinder temperatures of the three engines at nearly the same operating conditions of charge-air flow, fuel-air ratio, and cooling-air pressure drop paralleled predicted temperatures for the same conditions. This result was found to be true for a limited period of engine running time, this period coinciding with the time during which the cooling-correlation data were taken.
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Altitude cooling investigation of the R-2800-21 engine in the P-47G airplane II : investigation of the engine & airplane variables affecting the cylinder temperature distribution

Altitude cooling investigation of the R-2800-21 engine in the P-47G airplane II : investigation of the engine & airplane variables affecting the cylinder temperature distribution

Date: October 9, 1946
Creator: Pesman, Gerard J
Description: The data obtained from cooling tests of an R-2800-21 engine installed in a p-47G airplane were studied to determine which engine and airplane operation variables were mainly responsible for the extremely uneven temperature distribution among the 18 engine cylinders obtained at the medium and high engine-power conditions. The tests consisted of flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The results of the study showed that a flow condition in the induction system associated with the wide-open throttle position, which affected either the fuel air or charge distribution, was primarily responsible for the uneven temperature distribution. For the range of fuel-air ratios tested (0.080 to 0.102), the temperature distribution remained essentially unchanged. The individual effects of thrust-axis inclination, cowl-flap opening, and quantity of auxiliary air were found to be secondary in importance. At low angles of throttle opening, engine speed was found to have little effect on the temperature pattern.
Contributing Partner: UNT Libraries Government Documents Department
Altitude cooling investigation of the R-2800-21 engine in the P-47g airplane III : individual-cylinder temperature reduction by means of intake-pipe throttle and by coolant injection

Altitude cooling investigation of the R-2800-21 engine in the P-47g airplane III : individual-cylinder temperature reduction by means of intake-pipe throttle and by coolant injection

Date: October 9, 1946
Creator: Bell, E Barton
Description: Flight tests were conducted on a R-2800-21 engine in the P-47G airplane to determine the effect on the wall temperatures of cylinder 10 of throttling the charge in the intake pipe and of injecting a water-ethanol coolant into the intake pipe. Cylinder 10 was chosen for this investigation because it runs abnormally hot (head temperatures of the order of 45 F higher than those of the next hottest cylinder) at the medium and high-power conditions. Tests with interchanged cylinders showed that the excessive temperatures of cylinder 10 were inherent in the cylinder location and were not due to the mechanical condition of the cylinder assembly. Throttling the charge in the intake pipe is a simpler method than coolant injection into the intake pipe particularly when only one cylinder is considerably hotter than any other. Coolant injection into the individual cylinders is a more efficient method than throttling in the intake pipe and is warranted when several cylinders are to be cooled or when parts of the complex equipment required are already available.
Contributing Partner: UNT Libraries Government Documents Department