Report presenting shock-position controls designed to actuate the translating spike and variable bypass of a variable-geometry inlet in the 8- by 6-foot supersonic tunnel. The operation of the inlet was observed in combination with a J34 turbojet engine at a range of Mach numbers. Results regarding terminal-shock-positioning control systems and combination control are provided.

From Introduction: "In the present report, the results for the wings and bodies of revolution alone are first analyzed in comparison with exiting theory."

Report presenting a simplified method for obtaining free-flight measurements of damping in roll through the use of rocket-powered models. Initial configurations have been tested for a range of Mach numbers. Results regarding the rolling velocity with two different airfoil sections and damping-in-roll coefficient are provided.

Contains low-speed longitudinal stability characteristics of a 52 degree sweptback wing of aspect ratio 2.88, taper ratio 0.625, and NACA 64 (sub 1)-112 airfoil sections normal to the 0.282-chord line, in combination with split flaps, leading-edge flaps, and upper-surface fences. Low-wing and midwing-fuselage aerodynamic characteristics are presented with and without a horizontal tail at various vertical locations. Tests were conducted at a Reynolds number of 6.8 x 10(exp 6).

Report presenting the results of a wind-tunnel investigation of the lift and moment characteristics of four 10-percent-thick circular-arc airfoil sections. Increases in the trailing-edge thickness were found to result in increases in maximum lift coefficient and lift-curve slope at all Mach numbers as well as increases in lift-divergence Mach number at all lift coefficients.

Memorandum presenting an investigation of the problem of performance losses occurring when airplanes equipped with afterburner and cooling-air ejector installations are flown with the afterburner inoperative. Two sources of the performance losses occurring under some operation conditions were identified: an overexpansion of the propulsive jet and an internal shock system and the excessive pumping action resulting from the off-design.

From Summary: "The spontaneous ignition temperatures of 94 pure hydrocarbons and 15 fuels and commercial fluids were determined by a crucible method. The resulting data for the pure compounds are presented as functions of hydrocarbon structure."

"A method is presented for calculating wing characteristics by lifting-line theory using nonlinear section lift data. Material from various sources is combined with some original work into the single complete method described. Multhopp's systems of multipliers are employed to obtain the induced angle of attack directly from the spanwise lift distribution. Equations are developed for obtaining these multipliers for any even number of spanwise stations, and values are tabulated for 10 stations along the semispan for asymmetrical, symmetrical, and antisymmetrical lift distributions" (p. 1).

"In the first part, the boundary conditions for an open wind tunnel (incompressible flow) are examined with special reference to the effects of the closed entrance and exit sections. In the second part, solutions are derived for four types of two-dimensional open tunnels, including one in which the pressures on the two free surfaces are not equal. In the third part, a general method is given for calculating the boundary effect in an open circular wind tunnel of finite jet length" (p. 509).

Memorandum presenting an axial-flow turbojet engine operated on a sea-level static test stand to determine whether or not detectable signals were present in pressures and blade stresses that are usable as stall warnings in control applications. Surge and stall behavior were closely examined for the unique characteristics that could be used to control engine behavior in the vicinity of surge and stall. Results regarding a steady-state survey, acceleration study, investigation of an optimalizing technique, and an examination of engine damage are provided.

Report discussing the cooling characteristics of a 14-cylinder double-row radial air-cooled engine in a four-engine airplane. The effects of charge-air flow, cooling-air pressure drop, and fuel-air ratio on the cooling characteristics were measured separately. The cooling equation, rear middle-barrel temperature, cooling-limited manifold pressure, and maximum cruising power versus temperature-limited power are described.

"An experimental investigation of the stage performance of the J71 three-stage turbine at design speed and pressure ratio was conducted as part of a program involving research on the design and operational characteristics of high-work-output multistage axial-flow turbines. The investigation indicated that the over-all work output of the turbine based on temperature measurements at design speed and pressure ratio was 95 percent of the design value, with the greatest loss in work output and efficiency occurring in the first stage. Choking in the second-stage stator over most of the pressure ratios investigated prevented the attainment of design first-stage work output and also prevented any increase in work output of the first stage with increasing over-all pressure ratio at design speed" (p. 1).

"As part of an investigation to increase the power output of the V-1710-93 engine at altitude, the engine-stage supercharger was combined with a constant-area vaneless diffuser designed to improve the performance of the engine-stage supercharger at the rated engine operating point. The performance of the modified supercharger was investigated in a variable-component supercharger test rig and compared with that of the standard supercharger with an 8-vaned diffuser. A separate evaluation of the component efficiencies and a study of the flow characteristics of the modified supercharger was made possible by internal diffuser instrumentation" (p. 1).

Memorandum presenting a determination of the external-shock drags of supersonic inlets with circular cross sections from shadow photographs at a Mach number of 2.70 for a low-external-compression and a high-external-compression inlet. The calculated mass flow for both types of inlets showed reasonably good agreement with the measured values. Results as determined by the characteristics method and the approximate method are provided.

An investigation of a large group of related airfoils was made in the NACA variable-density wind tunnel at a large value of the Reynolds number. The tests were made to provide data that may be directly employed for a rational choice of the most suitable airfoil section for a given application. The variation of the aerodynamic characteristics with variations in thickness and mean-line form were systematically studied. (author).

"A flight test of the Aero jet Engineering Corporation's 7KS-6000 T-27 Jato rocket motor was conducted at the Langley Pilotless Aircraft Research Station at Wallops Island, Va, to determine the flight performance characteristics of the motor. The flight test imposed an absolute longitudinal acceleration of 9.8 g upon the rocket motor at 2.8 seconds after launching. The total impulse developed by the motor was 43,400 pound-seconds, and the thrusting time was 7.58 seconds" (p. 1).

The acceleration characteristics, in the region of maximum acceleration and compressor stall and surge, of an axial-flow turbojet engine with a fixed-area exhaust nozzle were determined by subjecting the engine to fuel flow steps, ramps, and ramps with a sine wave superimposed. From the data obtained, the effectiveness of an optimalizer type of control for this engine was evaluated. At all speeds above 40 percent of rated, a maximum acceleration was not obtained until the engine reached the point of stall or surge. A sharp drop, as high as 80 percent of maximum, in acceleration then occurred as the compressor entered surge of stall. With the maximum acceleration occurring at the point of surge or stall, the optimalizer-type control could not prevent the engine from entering surge or stall. Effective operation of the control may still be possible by sensing the sharp drop in acceleration experienced at the point of stall or surge and using this signal to limit fuel flow. The success of this type of operation would depend on the magnitude of the stall-recovery hysteresis.