Report presenting an investigation of the low-speed power-on stability and control characteristics of a free-flying model of the North American X-15 airplane. Results regarding the longitudinal stability and control, lateral stability, and lateral control are provided. Longitudinal stability was low, but it was considered to be satisfactory up to an angle of attack of about 30 degrees.

Memorandum presenting a model of a 60 degree delta-wing bomber with strut-mounted Siamese nacelles, which was designed, with the use of a symmetrical fuselage indentation, to have a smooth average area distribution at a Mach number of 1.20. The results show that the configuration drag rise was significantly higher than that from the equivalent-body tests and area-rule theory throughout the Mach number range. Results regarding total drag and pressure drag are provided.

"Theoretical rocket performance for equilibrium composition during expansion was calculated for JP-4 fuel with several fluorine-oxygen mixtures for a range of pressure ratios and oxidant-fuel ratios. The parameters included are specific impulse, combustion-chamber temperature, nozzle-exit temperature, molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, isentropic exponent, viscosity, thermal conductivity, and equilibrium gas compositions. A correlation is given for the effect of chamber pressure on several of the parameters" (p. 1).

Report presenting limited flight-test data obtained from an automatically controlled interceptor during runs in which oscillatory rolling motions occurred that were then compared to the pilot's comments about his ability to tolerate the imposed lateral oscillations. The alleviation of the undesirable effects of oscillatory lateral accelerations and their effects on piloting task were also considered. The marginally tolerable limit of acceleration forces on the pilot's head was found to be about 0.4 to 0.5g.

Report presenting theoretical rocket performance for frozen and equilibrium composition during expansion for the propellant combination of liquid hydrogen and liquid fluorine at a chamber pressure of 600 pounds per square inch absolute and several pressure ratios and oxidant-fuel ratios. The parameters included were specific impulse, combustion-chamber temperature, nozzle-exit temperature, molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, isentropic exponent, viscosity, and thermal conductivity.

"An investigation has been made in the Langley 4-by-4-foot supersonic pressure tunnel to determine the aerodynamic characteristics of a series of missile configurations having low-aspect-ratio wings at a Mach number of 2.01. The effects of wing plan form and size, length-diameter ratio, forebody and afterbody length, boattailed and flared afterbodies, and component force and moment data are presented for combined angles of attack and sideslip to about 28 degrees. No analysis of the data was made in this report" (p. 1).

Report presenting an investigation to determine the effects of spanwise and chordwise external store location on the aerodynamic characteristics of a cambered 45 degree sweptback wing-body configuration at a range of Mach numbers. Information about the drag characteristics of the various configurations, lift characteristics, and longitudinal stability characteristics is presented.

Report presenting an investigation to determine whether the low-lift drag of a rocket-model airplane-like configuration could be reduced at transonic and low supersonic Mach numbers by reducing wing thickness while external braces were used to provide the necessary bending strength. The investigation was conducted with two rocket models of aspect ratio 3.04, and unswept braced tapered wings mounted on fuselages with the same fineness ratios and cross-sectional area distributions. Data was compared to a previous study involving a model with a thicker cantilever wing.

From Introduction: "The results of an investigation of the low-speed static stability of a simplified model of such an arrangement having one of the airfoils placed vertically on top of the body and the other two as wing panels having negative dihedral are presented in reference 1. In order to provide information for predicting the effects of changes in the basic configuration on the low-speed stability characteristics presented in reference 1, additional measurements have been made."

A study of the effect of fuel-orifice diameter on the performance of heptane-oxygen rocket engines with single-element injectors. Five engines with a range of thrust were tested with parallel-sheet, triplet, and parallel-jet injectors. Decreasing the fuel-orifice diameter was found to increase the performance for a fixed chamber length. Results regarding injector performance and a comparison of experimental and analytical results are provided.

Report presenting an investigation to determine if the combined stress-rupture plus fatigue strengths of three groups of Waspaloy with different aging treatments and/or molybdenum contents could be correlated with their stress-rupture ductilities and notch-rupture strengths. Waspaloy is of interest as a gas turbine-bucket alloy because it has low strategic material content and relatively good stress-rupture properties. Results regarding metallurgical evaluation of the failed specimens are also provided.

Report presenting the performance of two stator-blade shapes with and without boric oxide deposits, which was determined in a two-dimensional cascade. The differences between the blades were the amount of curvature and suction-surface diffusion downstream of the throat. Results regarding the cascade throat area, boundary-layer momentum thickness, total-pressure ratio, and exit flow angle and tangential component of velocity.

Memorandum presenting an investigation at M = 2.01 in the 4- by 4-foot supersonic pressure tunnel to determine the effect of a series of nacelles on the longitudinal stability characteristics of a sweptback wing-body combination. Nacelle shape and position were varied on a configuration with a 6-percent-thick wing with an aspect ratio of 3.5, a taper ratio of 0.2, and 47 degrees of sweep at the quarter chord.

Report presenting an investigation to study the aerodynamic problems associated with a turbine design for a mode of engine operation which utilizes turbine stator adjustment to maintain a fixed compressor operating point. An indication of the turbine requirements for a particular compressor operating point indicated that a feasible sing-stage air-cooled turbine design could be obtained within reasonable aerodynamic limits. Results regarding the performance of the turbine, pressure ratios, and operational requirements are provided.

Report presenting an investigation of a conservatively designed experimental cold-air turbine with and without a shroud band on the rotor blades. The tip of the rotor blade was oriented toward the tangential direction so that the adverse effect of blade-tip scraping would not be appreciable. The efficiency for the unshrouded-rotor configuration was about one point higher than for the shrouded rotor.

Memorandum presenting an experimental investigation of the aerodynamic loading on one blade and of a two-blade teetering rotor conducted in forward flight for a tip-speed-ratio range of 0.08 to 0.29 at a disk loading of about 2.4 pounds per square foot and a tip speed of about 480 feet per second. Chordwise loading distributions at five spanwise stations and the variation of section loading and total blade lift with azimuth position are presented. Results regarding the performance data, section aerodynamic loading, spanwise loading distribution, total blade lift, and rotor-disk load distribution are provided.

Report presenting a theoretical investigation of the attack phase of an automatically controlled interceptor. Three types of control systems were simulated on an analog computer: a modern high-speed interceptor, a dynamically perfect radar-controlled director-type guidance system for a lead-collision course, and a velocity-type automatic pilot. The primary flight maneuver tested was a 5g climbing turn with roll and acceleration commands applied simultaneously.

Report presenting an exploratory investigation of the effectiveness of outboard horizontal tails in reducing the static longitudinal stability changes with lift coefficient associated with many sweptback wings. The results indicated that outboard horizontal tails can be a very effective means of counteracting the trend toward longitudinal instability characteristics of many sweptback wings. Results regarding the effects of changes in horizontal-tail position, effects of wing fences, average downwash at the tail, effects of changing tail size, lift, drag, and pitching-moment characteristics, and effects of flaps are provided.

This report presents the results of a study made of the influence of several variables on the pressure decrease accompanying injection of a relatively cool liquid into a heated compressed gas. Indirectly, this pressure decrease and the time rate of change of it are indicative of the total heat transferred as well as the rate of heat transfer between the gas and the injected liquid. Air, nitrogen, and carbon dioxide were used as ambient gases; diesel fuel and benzene were the injected liquids. The gas densities and gas-fuel ratios covered approximately the range used in compression-ignition engines. The gas temperatures ranged from 150 degrees c. to 350 degrees c.

"The effects of air flow on fuel spray and flame formation in a high-speed compression-ignition engine have been investigated by means of the NACA combustion apparatus. The process was studied by examining high-speed motion pictures taken at the rate of 2,200 frames a second. The combustion chamber was of the flat-disk type used in previous experiments with this apparatus. The air flow was produced by a rectangular displacer mounted on top of the engine piston. Three fuel-injection nozzles were tested: a 0.020-inch single-orifice nozzle, a 6-orifice nozzle, and a slit nozzle" (p. 281).

Pressures were simultaneously measured in the variable-density tunnel at 54 orifices distributed over the midspan section of 5 by 30 inch rectangular model of the NACA 4412 airfoil at 17 angles of attack ranging from -20 degrees to 30 degrees at a Reynolds number of approximately 3,000,000. Accurate data were thus obtained for studying the deviations of the results of potential-flow theory from measured results. The results of the analysis and a discussion of the experimental technique are presented.

Memorandum presenting a description of the Ames supersonic free-flight wind tunnel, which is a new piece of equipment for aerodynamic research at high supersonic Mach numbers. It has a wide Mach number range extending from low supersonic speeds to Mach numbers in excess of 10. The air stream in the tunnel is imperfect, mainly due to a symmetrical pair of oblique shock waves which reflect down the test section.

Report presents the results of an investigation conducted to study the effects of the inert gases, argon and helium, upon flame speed and expansion ratio in exploding mixtures of carbon monoxide, oxygen and water. For the particular gas mixtures investigated the results show that: (1) With the possible exception of helium in small amounts the addition of inert gas always produces decreased flame speed and expansion ratio; (2) like volumes of argon and helium have very different effects upon flame speed but practically the same effect upon expansion ratio; and (3) the difference in the effect of these two gases upon speed is independent of the ratio of carbon monoxide to oxygen. A discussion of some possible modes by which inert gases may produce the observed effects is included.

Report presents the results of wind tunnel tests of the Clark Y, the NACA 23012 and the NACA 23021 airfoils equipped with full-span ordinary flaps and with full-span simple split flaps. The principal object of the tests was to determine the characteristics of the airfoils with ordinary flaps and in addition, to determine the relative merits of the various airfoils when equipped with either ordinary flaps or with simple split flaps. The Clark Y airfoil was tested with 3 widths of ordinary flap, 10, 20, and 30 percent of the airfoil chord.