From Summary: "Theoretical performance data including nozzle-exit temperature, specific impulse, volume specific impulse and composition, temperature, and mean molecular weight of reaction products based on frozen equilibrium and isentropic expansion are presented for 13 propellant combinations at reaction pressure of 300 pounds per square inch absolute and expansion ratio of 20.4. On basis of maximum specific impulse alone, five fuels had the following order for any given oxidant: liquid hydrogen, hydrazine, liquid ammonia, and either hydrazine hydrate or hydroxylamine. Three oxidants with a given fuel had the following order: liquid ozone, liquid oxygen, and 100-percent hydrogen peroxide."

Measured values of lift, drag, and pitching moment at a Mach number of 1.53 and Reynolds numbers of 0.31, 0.62, and 0.84 million are presented for a wing-fuselage combination having a wing leading-edge sweep angle of 63 degrees, an aspect ratio of 3.42, a taper ratio of 0.25, and an NACA 64A006 section in the stream direction. Data are also presented for sweep angles of 57.0 degrees, 60.4 degrees, 67.0 degrees, and 69.9 degrees. The experimentally determined characteristics were less favorable than indicated by the linear theory but the experimental and theoretical trends with sweep were in good agreement. Boundary-layer-flow tests showed that laminar boundary-layer separation was the primary cause of the differences between experiment and theory.

Report presenting an investigation of icing and ice protection at the inlet of a turbojet engine in the altitude wind tunnel. A method of ice protection was studied that uses hot gas bled from a turbine inlet and injected into the air stream ahead of the compressor inlet. Ice was either prevented or accumulated slowly at various engine speed levels.

From Introduction: "The single purpose of this paper is to make available the data obtained from tests of these two Clark Y section propellers as quickly as possible with no attempt being made to analyze the results or to compare them with other high-speed-propeller test results."

From Summary: "Motion pictures at camera speeds up to 3000 frames per second were taken of the combustion of liquid oxygen and gasoline in a 100-pound-thrust rocket engine. The engine consisted of thin contour and injection plates clamped between two clear plastic sheets forming a two-dimensional engine with a view of the entire combustion chamber and nozzle. A photographic investigation was made of the effect of seven methods of propellant injection on the uniformity of combustion. From the photographs, it was found that the flame front extended almost to the faces of the injectors with most of the injection methods, all the injection systems resulted in a considerable nonuniformity of combustion, and luminosity rapidly decreased in the divergent part of the nozzle."

"A theoretical analysis is presented for obtaining by use of Theodorsen's propeller theory the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers" (p. 1).

From Summary: "An investigation was conducted in the 6- by 6-foot test section of the Langley stability tunnel on a modified Koppers Aeromatic wind-driven impeller-generator combination. This investigation consisted of a few fixed pitch tests and a series of variable pitch tests. The fixed pitch tests indicated that the impeller should operate between the blade-pitch angles of 20 and 32deg at the specified output of 11.7 kilowatts in order to remain within the specified rotational speed of from 5000 to 8000 rpm for airspeeds of from 130 to 175 miles per hour. The requirement that the impeller maintain rotational speeds of - between 5000 and 8000 rpm as the impeller output varied from 0 to ll.7 kilowatts at airspeeds of from 130 to 175 miles per hour was not met at any time during the variable pitch tests."

"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" (p. 1).

"An altitude-wind-tunnel investigation has been made to determine the performance of a Curtiss 732-1C2-0 four-blade propeller on a YP-47M airplane at high blade loadings and engine power. Propeller characteristics were obtained for a range of power coefficients from 0.30 to 1.00 at free-stream Mach numbers of 0.40 and .50" (p. 1).

"An investigation was conducted in the Cleveland altitude wind tunnel to determine the performance of a Curtiss propeller with four 838-1C2-1SR1 blades on a YP-47M airplane at high blade loadings and engine powers. The study was made for a range of power coefficients between 0.30 and 1.00 at free-stream Mach numbers of 0.40 and 0.50. The results of the force measurements indicate primarily the trend of propeller efficiency for changes in power coefficient or advance-diameter ratio, inasmuch as corrections for the effects of tunnel-wall constriction on the installation have not been applied" (p. 1).

Wind tunnel tests of the 0.16-scale Douglas MX-656 model were made at low and high subsonic Mach numbers to investigate the static longitudinal- and lateral stability characteristics. The tests shows that undesirable changes in longitudinal stability at the stall were apparently caused by an altered downwash pattern at the tail. The jettisonable nose fins were highly destabilizing. Compressibility effects for the test Mach numbers were not detrimental to the longitudinal- or lateral-stability characteristics.

"The spin and recovery characteristics of the Curtiss-Wright XP-87 airplane, as well as the spin-recovery parachute requirements, the control forces that would be encountered in the spin, and the best method for the crew to attempt an emergency escape, are presented in this report. The characteristics were estimated rather than determined by model tests because the XP-87 dimensional and mass characteristics were considered to be noncritical and because data were available from model tests of several similar airplanes. The study indicated that the recovery characteristics of the airplane will be satisfactory for all loadings if the controls are reversed fully and rapidly" (p. 1).

The results obtained from gust and draft velocity measurements within thunderstorms for the period July 24, 1946 to August 6, 1946 at Orlando, Florida are presented herein. These data are summarized in tables I and II and are of the type presented in reference 1 for previous flights. In two thunderstorm traverses, indications of ambient-air temperature were obtained from photo-observer records. These data are summarized in table III.

"An investigation of the 19XB-2A gas turbine is being conducted at the Cleveland laboratory to determine the effect on turbine performance of various inlet pressures, inlet temperatures, pressure ratios, and wheel speeds. The engine of which this turbine is a component is designed to operate at an air flow of 30 pounds per second at a compressor rotor speed of 17,000 rpm at sea-level conditions. At these conditions the total-pressure ratio is 2.08 across the turbine and the turbine inlet total temperature is 2000 degrees R" (p. 1).

From Summary: "An investigation was conducted on a 12-cylinder V-type liquid-cooled aircraft engine of 1710-cubic-inch displacement to determine the minimum specific fuel consumption at constant cruising engine speed and compression ratios of 6.65, 7.93, and 9.68. At each compression ratio, the effect.of the following variables was investigated at manifold pressures of 28, 34, 40, and 50 inches of mercury absolute: temperature of the inlet-air to the auxiliary-stage supercharger, fuel-air ratio, and spark advance. Standard sea-level atmospheric pressure was maintained at the auxiliary-stage supercharger inlet and the exhaust pressure was atmospheric."

Report presenting tests of an NACA 4-(5)(08)-03 two-blade propeller in the 8-foot high-speed tunnel for blade angles of 45 and 60 degrees extending the Mach number range from that of previous tests of the propeller up to Mach number 0.913. When the forward speed was increased from a low value to a forward Mach number of 0.90, the loss in peak efficiency was found to be not more than 47 percent.

Report presenting flight tests of rocket-powered models at supersonic speeds to determine the effect of nose fineness ratio of winged bodies on total and component drag at high Mach numbers. Wingless models of three nose fineness ratios and winged models of two nose fineness ratios flown through a range of Mach numbers. Results regarding total drag, body drag, and wing drag are provided.

Report presenting the results from tank landing and take-off tests with a dynamic model of a hypothetical jet-propelled airplane equipped with NACA hydro-skis. Results regarding landing tests, take-off tests, and practical considerations for the creation of hydro-ski configurations are provided. The hydro-skis suitable for flush retraction into streamline fuselages do appear to offer a practical means of water take-offs and landings.

Report presenting wind-tunnel testing to determine the low-speed lift, drag, and pitching-moment characteristics of a 40 degree sweptback wing with high-lift and stall-control flaps and a fuselage with a fineness ratio of 10.2 to 1. Low, medium, and high-wing-fuselage combinations were tested at high Reynolds numbers. Results regarding the high-lift and stall-control flaps and wing-fuselage combinations are provided.

Report presenting an analysis of the spanwise loading using two different methods on the wing of an airplane for which pressure-distribution measurements were available from flight tests up to a Mach number of 0.866. A comparison between measured and calculated distributions was made on the basis of equal wing-panel normal-force coefficients.

Report presenting a wind-tunnel investigation on a 42 degree sweptback-wing model to determine the lateral control characteristics of a plug-aileron configuration. The configuration consisted of six segments extending from the wing 20-percent-span to the wing 80-percent-span stations and with the center of each plug on the wing 70-percent-chord line. Results regarding wing aerodynamic characteristics and lateral control characteristics are provided.

Report presenting aerodynamic and icing investigations conducted in the icing research tunnel on a model of a turbojet-engine nacelle with a long straight air inlet in order to provide basic design criteria for hot-gas blowback systems. The most uniform temperature distribution was obtained with a bleedback of 4.4 percent at a gas temperature of 1000 degrees Fahrenheit and resulted in an average dry-air-temperature rise of 46 degrees Fahrenheit.

Report presenting the results of a wind-tunnel investigation of the effects of variation of trailing-edge angle and leading-edge radius on the aerodynamic characteristics of a 10-percent-chord-thick airfoil section at a range of Mach numbers.

Report presenting an altitude-chamber investigation to determine the altitude performance characteristics of the British Rolls-Royce Nene II turbojet engine with an 18.41-inch-diameter jet nozzles. Testing occurred at a range of simulated altitudes and ram-pressure ratios. Results regarding the simulated flight performance, generalized performance, and effect of jet-nozzle area on performance are provided.