"The trajectories of waterdrops in air flowing over airfoils are determined for three airfoil - angle-of-attack combinations using the differential analyzer to solve the differential equations of motion of the waterdrops. From these trajectories the rate of water impingement, the area of impingement, and the distribution of impingement are determined as functions of two dimensionless moduli. Comparisons are made of the rate of water impingement on these airfoils and the rate of water impingement on cylinders" (p. 1).

From Summary: "The trajectories of waterdrops in air flowing over airfoils are determined for three airfoil-angle-of-attack combinations using the differential analyzer to solve the differential equations of motion of the waterdrops. From these trajectories the rate of water impingement, the area of impingement, and the distribution of impingement are determined as functions of two dimensionless moduli. Comparisons are made of the rate of water impingement on these airfoils and the rate of water impingement on cylinders."

"A device has been developed which measures the velocity of sound in fluids at stagnation and is especially adaptable to turbine and compressor testing for which the constituency of the working fluid may be in doubt. By utilizing the shaft frequency of a rotary compressor, the instrument can also be used to provide a direct measurement of the compressor Mach number (ratio of blade-tip velocity to inlet velocity of sound at stagnation). A Helmholtz resonator is employed in the measurement of the sound velocity" (p. 1).

Report presenting the results of a study of the movement of shocks on a three-dimensional wing with and without aileron flutter occurring. The studies include a number of changes and variations to the wing and control. Results for the standard wing and aileron, spoilers at 50 percent chord, upper and lower surface, faired bumps at the 50-percent-chord and 70-percent-chord positions, variations of thickness ratio along the span, vent holes between upper and lower surface, aileron-contour change, aileron mass overbalance, dampers, wing flutter, buffeting forces on fixed controls, and static characteristics are provided.

Memorandum presenting a general treatment of compressible flow in ejectors with friction in the mixing tube included. A secondary object is to show the application of the flow theory to the calculation of the effect of ejector addition on thrust of jet-propelled airplanes and missiles. Results regarding the outline of methods of applying the general theory to some other problems and future explorations of ejector problems are provided.

Report presenting flight testing on two propeller-driven airplanes with wings of NACA 66-series and NACA 230-series airfoil sections to determine the effect of deflecting the landing flaps upward on the high-speed longitudinal-control characteristics.

From Summary: "The trajectories of waterdrops in air flowing over airfoils are determined for three airfoil-angle-of-attack combinations using the differential analyzer to solve the differential equations of motion of the waterdrops. From these trajectories the rate of water impingement, the area of impingement, and the distribution of impingement are determined as functions of two dimensionless moduli. Comparisons are made of the rate of water impingement on these airfoils and the rate of water impingement on cylinders."

Report presenting testing of three rocket-powered models with Douglas D-558-2 wings as horizontal fins with scaled structural parameters to determine whether the possibility of wing flutter due to torsion and bending exists in full-scale airplanes at transonic speeds. No wing flutter was present in the models tested, but pitching oscillation developed as it passed into the transonic range.

Report presenting the effects of changes in Reynolds number on the longitudinal aerodynamic characteristics of a 52 degree sweptback wing with an aspect ratio of 2.88 and NACA 64(sub 1)-112 airfoil sections. The model was tested with the leading edge both smooth and rough. Results regarding force and pitching-moment results, flow observations, and discussion of force and moment characteristics are provided.

Memorandum presenting an exploratory investigation to determine the aerodynamic effects of camber on a 60 degree apex delta-wing model conducted in the 300 mph 7- by 10-foot tunnel. Camber variation was accomplished through the deflection of full-span round and 25 degree beveled leading-edge flaps on a flat-sided triangular plan-form wing.

Memorandum presenting limited data covering extension of the transonic-flight tests of the XS-1 airplane. The data show that successful flight to a Mach number of 1.35 has been achieved at altitudes up to 40,000 feet.

Report presenting a study of the flight characteristics of the canard configuration at transonic and supersonic speeds. Known problems concerning the low-speed characteristics of the canard are also investigated.

Report presenting an investigation of the performance of a single can-type combustor designed for a turbojet engine equipped with an 11-stage axial-flow compressor and a single-stage turbine. The investigation was conducted to determine the altitude operational limits of the engine for two fuels, combustion efficiencies at various simulated conditions of altitude and engine speed, combustor-outlet temperature distribution for several altitudes at constant engine speed, and combustor total-pressure drop.

"The NACA is engaged in a program to evaluate the performance of fuels conforming to AN-F-58 specification in both full-scale engines and single combustors. This research memorandum constitutes an interim report on the results obtained on single cosibustors" (p. 1).

Report presenting an investigation of a German Jumo 004 combustor under conditions simulating zero-ram operation of a 24C jet-propulsion engine over ranges of altitude and engine speed to obtain the altitude operating limits and characteristics. Combustion efficiency, outlet-temperature distribution, and total-pressure drop were determined. The performance of the combustor with 62-octane and JP-1 fuels were also compared.

Memorandum presenting the results of a wind-tunnel investigation of the low-speed aerodynamic characteristics of a horizontal-tail model of aspect ratio 2 with an unswept plan form and of a two-dimensional model. The two-dimensional model provides data which can be used as the basis for computing the three-dimensional lift and hinge-moment parameters by the lifting-surface-theory procedure. Results regarding the effectiveness and hinge-moment parameters, static longitudinal stability, scale effect, effect of standard roughness, and effect of removing the elevator nose seal are provided.

Report presenting the results of an analytical investigation, which demonstrated that the inlet of a turbojet engine can be protected from ice accretions by bleeding hot gases from other locations within the engine to the inlet without undue loss in thrust. Results regarding the bleedback requirements, engine performance, effect of nozzle area, mixing efficiency, and seriousness of thrust losses are provided.

Report discussing an investigation on the effect of engine skew on the directional and lateral control characteristics of a single-engine airplane with a single-rotating propeller. The estimated and test results showed an advantage to skewing the propeller, as it assists with overcoming inadequate rudder control in power-on flight and aileron control, especially with flaps deflected.

An investigation on various can-type burners in a Bumblebee 18-inch ram jet under controlled conditions of pressure altitude and ram pressure ratio was conducted in the NACA Lewis altitude wind tunnel with kerosene as fuel. The performance of the following can-type burner configurations was better than that of the other burner configurations investigated: (1) a flame holder having a two-pitch alinement of perforations, 0.07-inch-wide cooling slots, and an arrangement of fuel nozzles located within an annulus having a mean radius of 7.24 inches; and (2) a flame holder having a zero-pitch alinement of perforations, 0.16-inch-wide cooling slots, and an annulus of fuel nozzles having a mean radius of 6.89 inches.

"Bench runs of a modified V-1710-93 engine equipped with a two-stage supercharger, interstage carburetor, aftercooler assembly, and backfire screens have been made at a simulated altitude of 29,000 feet to determine the effect of several induction-system modifications on the engine and supercharger performance. The standard guide vanes on the auxiliary- and engine-stage superchargers were replaced by rotating guide vanes with a parabolic blade profile. The auxiliary-stage inlet elbow and interstage duct were replaced with new units of NACA design. These modifications were made one at a time and data were obtained after each change to determine the effect of each modification" (p. 1).

The hydrodynamic characteristics of an aerodynamically refined planing-tail hull were determined from dynamic model tests in Langley tank no. 2. Stable take-off could be made for a wide range of locations of the center of gravity. The lower porpoising limit peak was high, but no upper limit was encountered. Resistance was high, being about the same as that of float seaplanes. A reasonable range of trims for stable landings was available only in the aft range of center-of-gravity locations.

"An investigation of the air-stream fluctuations at the tail of the D-558-1 airplane has been made at high speed for the purpose of determining the vertical region in which the horizontal tail may be placed without becoming subject to tail buffeting. The investigation was made for a range of Mach numbers from 0.775 to 0.907, and a range of vertical positions at the tall to include two proposed horizontal-tail positions. The tests were made at two angles of attack, 0,2 deg. and 4.2 deg., representative, of the angles of attack for high-speed level flight and a pull-out condition" (p. 1).

"Flight tests to determine propeller performance have been made of a Curtiss No. 838-102-18 three-blade propeller having trailing-edge extensions on a Republic P-47D-28 airplane in climb and high speed. These tests are a part of a general propeller flight-test program at the Langley Laboratory of the National Advisory Committee for Aeronautics. Results of climb tests indicate that when power is changed from approximately 1475 horsepower at 2550 rpm (roughly normal power) to 2400 horsepower at 2700 rpm (approximately military power) there is a loss in propeller efficiency of 3 percent at an altitude of 7000 feet, and 4 percent at 21,000 feet" (p. 1).

A 1/4 - scale model of the Naval Aircraft Factory float-wing convoy interceptor was tested in the Langley 7-by 10-foot tunnel to determine the longitudinal and lateral stability characteristics. The model was tested in the presence of a ground board to determine the effect of simulating the ground on the longitudinal characteristics.