Report presenting testing of a towed airplane model in the 19-foot pressure tunnel in conjunction with the development of a flutter testing technique. The model was equipped with an autopilot to keep the model flying straight and level in the tunnel while restrained only in drag. Results regarding period and cycles to damp to half amplitude, time histories, and motions of the flexible wing model are provided.

From Summary: "Flight measurements of the aerodynamic wing loads on the D-558-II airplane have been made in the Mach number range from 1.0 to 2.0. Nonlinear wing-panel characteristics occurred with variations in angle of attack. These nonlinear characteristics were apparent primarily at the lower supersonic speeds."

Report presenting a theory of reduction of convective heat transfer to a surface in supersonic flow by periodically imposing a large-scale vortical motion on the boundary layer and an experimental investigation of that theory. Results regarding the pulsating flow phenomena, heat-transfer characteristics, and aerodynamic characteristics are provided.

Report presenting the results of a wind-tunnel investigation to determine the effects of a variation in wing taper ratio on the longitudinal characteristics of a wing-body combination at a variety of Mach numbers. The wings had an aspect ratio of 3, an unswept midchord line, and an NACA 64A003 profile. Results regarding the lift and pitching-moment characteristics and drag characteristics are provided.

Report presenting wind-tunnel flutter testing at a range of Mach numbers conducted on a swept-wing towed airplane model equipped with an autopilot system. Results regarding the towed model tests, fixed-root tests, and a comparison between the calculated and experimental flutter characteristics are provided.

Memorandum presenting a supersonic wind-tunnel investigation of the origin and distribution of store interference in the 4- by 4-foot supersonic pressure tunnel at Mach number 1.6 in which separate forces on a store, a fuselage, a swept wing, and a swept-wing-fuselage combination were measured. The store was separately sting-mounted on its own six-component internal balance and was traversed through a wide systematic range of spanwise, chordwise, and vertical positions.

Report presenting a full-scale, free-jet investigation to determine the performance of a side-inlet supersonic diffuser designed for a flight Mach number of 2.75. Several internal modifications made to improve diffuser-outlet flow uniformity were also evaluated. Results regarding the general characteristics of the diffuser and effect of diffuser modifications on flow distribution are provided.

Report presenting the results of a wind-tunnel investigation to determine the effects of various free-flight rocket-model booster-adapter configurations on the aerodynamic characteristics in pitch and sideslip of a swept-wing, fighter airplane model with a Mach number of 2.01. Results regarding the effect of adapter shape and aerodynamic characteristics of the model alone are provided.

"In the development of high temperature materials of the brittle category, the need to improve their impact strength for some applications has brought with it a demand for a simple machine for measuring impact resistance, both at room and elevated temperatures, and preferably one in which corrections such as the toss energy are negligible. This report describes such a machine and presents the results of some preliminary tests on the effect of temperature on impact strength of several alloys and cermets. A comparison is also given between the impact resistance of notched and unnotched specimens" (p. 1).

Report presenting information on the engine performance variations resulting from bleeding air from the compressor for turbine cooling, which is currently lacking. A thermodynamic-cycle investigation was conducted to determine the magnitude of the performance variations for a wide range of operating conditions for turboprop engines and for both afterburning and nonafterburning turbojet engines.

Report presenting testing of a supersonic mixed-flow compressor of large weight-flow capacity with a stator with swept and tilted blades was tested over a range of air tip speeds. As rotor speed increased, stage efficiency decreased continuously. Results regarding the overall compressor performance, flow fluctuations, and static-pressure distribution are provided.

From Introduction: "The resulting losses in performance have been studied in a number of analyses such as that reported in reference 1."

Report presenting testing of a 60-degree delta-wing-fuselage model with a 4-percent-thick airfoil section with large leading-edge radius in the 19-foot pressure tunnel to determine the effectiveness of porous-leading-edge suction in delaying and reducing the leading-edge separation and accompanying high drag. Results regarding the delta wing, including pump power, lift, pitching moment, pressure distributions, the clipped wing, and some comments on the application of leading-edge suction to delta wings are provided.

Memorandum presenting testing of an NACA 65(sub 06)A004 airfoil to determine the effects of a solid-strip spoiler on buffeting forces. Fluctuations of both section normal-force coefficient and of section pitching-moment coefficient are presented as functions of angle of attack and of section normal-force coefficient. Generally, the spoiler decreased the fluctuating section normal-force and pitching-moment coefficients if comparison is made at constant angle of attack and increased these coefficients if comparison is made at constant section normal-force coefficient.

From Introduction: "In comparison with the shaft-driven rotor, the jet rotor is shown in references 1 and 2 to provide direct reductions in helicopter empty weight and to increase the pay-load capacity by (1) eliminating the gear-reduction train between the rotor shaft and the power plant, (2) eliminating the antitorque tail rotor, and (3) using a power plant of low specific weight."

Report presenting studies of the final attack phase of an automatically controlled interceptor in flight and electronic simulators to investigate various airplane command and stabilization networks and to develop simple but adequate simulation techniques for the synthesis of automatic control systems. Results regarding automatic control with a simple command system, automatic control with the improved command system, and evaluation of the automatic control system in typical final attack maneuvers are provided.

From Introduction: "The purpose of this paper is to present an analysis of the data for the remaining airplanes where the data were sufficient to warrant analysis. The data analyzed represent totals of 351 to 5660 hours of operations with ten types of Navy airplanes and were recorded during the period 1949 to 1953."

Report presenting an experimental investigation to assess the effects of sweep and taper ratio on the longitudinal characteristics of a wing-body combination at a range of Mach numbers. The results indicated that increased leading-edge sweep caused a progressive decrease in lift-curve slope and the variation of Mach number of the lift-curve slope and static longitudinal stability. Results regarding the effect of sweep, effect of taper ratio, and comparison with results of a previous investigation are provided.

Report presenting an analysis of the maximum power thrust-minus-drag performance of several turbojet-engine air-inlet combinations over a wide range of flight conditions. The primary objective of the analysis was to use the experimentally determined drag and total-pressure-recovery characteristics to show the range of satisfactory performance of each of several fixed-geometry inlet configurations. Results regarding the performance at 35,000 feet, inlet design considerations, speed range of efficient normal-shock inlet performance, effect of altitude on performance of the fixed-geometry system, and effect of nonstandard air on the performance of a fixed-geometry system are provided.

Report presenting a method for analyzing each of the elements, boron, carbon, and hydrogen from the quantitative analysis of a single sample of an organoboron compound. The method is helpful for the analysis of volatile hydrocarbons and polynuclear aromatic compounds.

From Summary: "An experimental wind-tunnel investigation was conducted at Mach 1.9 to determine the pressures acting on the base of a multijet missile using unheated air and carbon dioxide as jet fluids. The variation of base pressure with jet static-pressure ratio was compared with results estimated for an axisymmetric single-jet model and some correlation was observed."

Report presenting a transonic compressor rotor with double-circular-arc blade sections, which was designed and tested to investigate the aerodynamic effects of using a short blade chord and a high aspect ratio and to obtain more blade-element data. Results regarding overall performance, rotor-inlet conditions, rotor-outlet conditions, and rotating-stall characteristics and blade vibrations are provided.

Preliminary results are presented from an investigation to determine the influence of afterbody geometry on the effects of a sonic propulsive jet at transonic speeds. The results presented are base pressure coefficient and afterbody pressure-drag coefficient as a function of jet pressure ratio for different values of Mach number and jet temperature. Geometric parameters investigated include boattail angle, jet-to-model diameter ratio, and jet-to-base diameter ratio.

Memorandum presenting an investigation of the effective thermal conductivities of powders, which included uranium oxide UO(sub 2) powder with a density of 59.5 percent of the density of the solid uranium oxide at a range of temperatures. Helium, argon, and nitrogen gases and mixtures of helium-argon and xenon-krypton gases were introduced into the powder void, and the experimental effective thermal conductivities of the gas-powder mixtures were determined.