Report presenting an investigation in the 20-foot free-spinning tunnel to determine the motions and trim conditions from 0 to 90 degrees angle of attack for the X-3 airplane, which is a supersonic airplane with an extremely long nose and s mall wing. Testing was conducted on several scales of models and component parts. Results from dynamic and static tests are provided.

Altitude-test-chamber investigation of effects of flame-holder blocked area and gutter width on performance of 28-inch diameter ram jet at simulated flight Mach number of 2.0 for altitudes from 40,000 to 55,000 feet was conducted at NACA Lewis laboratory. Ten flame holders investigated covered gutter widths from 1.00 to 2.50 inches and blocked areas from 40.5 to 62.0 percent of combustion-chamber area. Gutter width did not appreciably affect combustion efficiency.

From Introduction: "The wings were tested in combination with fuselage similar to the one used in the 7- by 10-foot wind-tunnel investigations. The results are reported herein and are compared with results for three similar model wings on the transonic bump (references 1, 2, and 3)."

Report presenting the results of a series of qualitative studies with tufts on three wings with sweepback angles of 30 degrees, 45 degrees, and 60 degrees, which show that under certain conditions, a leading-edge vortex can exist in the unsteady flow associated with a gust. The results indicated that if a wing in steady flight prior to entering a gust is at an angle of attack several degrees less than that at which vortex flow first begins in steady flow, it may penetrate the gust without having the vortex develop, even if its angle of attack is increased by the gust into the vortex-flow regime.

From Introduction: "The results of this complete evaluation of the altitude performance and operational characteristics of the two types of flame-holder and fuel-system configurations are reported herein.The starting limits of both configurations at a flight Mach number of 0.6 are also discussed."

Report presenting an investigation of the effect of combustion on diffusion in the fuel preparation zone of a ram-jet engine. The information was applied in the design of combustor to operate at lean fuel-air ratios.

The effect of spark repitition rate on the altitude ignition limits of a single tubular (turbojet engine) combustor was investigated. An increase in sparking rate from 3 to 140 sparks per second reduced the ignition limiting combustor-inlet pressure about 2 to 4 inches of mercury for air-flow rates of 1.87 and 2.80 pounds per second per square foot.520::At 3.75 pounds pe At 3.75 pounds per second per square foot, the corresponding reduction was 4 to 12 inches of mercury. The trend was similar for both low-and high-volatility fuels and for two spark-energy levels.

Report presenting an investigation of two versions of a type of forward underslung scoop mounted on a pointed fuselage in the supersonic blowdown tunnel. The scoop entrances were in the shape of a 60 degree sector of an annulus, but the sides of one scoop were sweptback, while the others were unswept. Results regarding the shadowgraphs and surface-pressure distributions and total-pressure recovery are provided.

Magnesium-hydrocarbon slurries containing a moderate proportion of petrolatum have physical properties such that they offer promise as experimental aircraft fuels. The settling of the magnesium is greatly retarded by the petrolatum, and the slurries can easily be remixed to their original condition after storage. Successive batches which have closely similar properties can be prepared readily. The apparent viscosity of these slurries increased rapidly with increasing magnesium concentration, with increasing petrolatum concentration, and with decreasing temperature. As the apparent viscosity increased, the extent of settling and the ease of remixing both decreased. Although no quantitative correlation was found between the properties of the slurry and those of the petrolatum, and no one petrolatum gave slurries which were best in all respects, one of the five petrolatum used was judged to be superior to the others.

From Summary: "The performance of jet fuel with an oxidant mixture containing 70 percent liquid fluorine and 30 percent liquid oxygen by weight was investigated in a 500-pound-thrust engine operating at a chamber pressure of 300 pounds per square inch absolute. A one-oxidant-on-one-fuel skewed-hole impinging-jet injector was evaluated in a chamber of characteristic length equal to 50 inches. A maximum experimental specific impulse of 268 pound-seconds per pound was obtained at 25 percent fuel, which corresponds to 96 percent of the maximum theoretical specific impulse based on frozen composition expansion."

Report presenting tests of rocket-propelled models at transonic speeds to compare the zero-lift drags of 45 degree sweptback wings with and without solid nacelles at the wing tips. The wing drag coefficient was lowered at high subsonic and supersonic speeds when the aspect ratio was reduced from 6.0 to 3.55. Results regarding the favorability of the wing-tip nacelles and the force-break Mach number of the varying configurations are also provided.

Report presenting testing to obtain the effects of changes in Mach number, thickness ratio, and angle of attack on the amplitude of the pressure pulsations on several airfoils at transonic speeds. The tests were performed on NACA 65A-series airfoils with thicknesses ranging from 4 to 12 percent chord at a range of Mach numbers and angles of attack. The relations of pressure pulsations to buffeting are also provided.

"The performance and operational characteristics of a Python turbine-propeller engine were investigated at simulated altitude conditions in the NACA Lewis altitude wind tunnel. In the performance phase, data were obtained over a range of engine speeds and exhaust nozzle areas at altitudes from 10,000 to 40,000 feet at a single cowl-inlet ram pressure ratio; independent control of engine speed and fuel flow was used to obtain a range of powers at each engine speed. Engine performance data obtained at a given altitude could not be used to predict performance accurately at other altitudes by use of the standard air pressure and temperature generalizing factors" (p. 1).

A typical inlet axial-flow compressor inlet stage, which was designed on the basis of constant total enthalpy with symmetrical velocity diagram at all radii, was investigated. At a tip speed of 1126 feet per second, a peak pressure ratio of 1.28 was obtained at an efficiency of 0.76. At a tip speed, the highest practical flow was 28 pounds per second per square foot frontal area with an efficiency of 0.78. Data for a rotor relative inlet Mach number range of from 0.5 to 0.875 indicates that the critical value for any stage radial element is approximately 0.80 for the stage investigated.

An investigation to determine the heat-shock resistant properties of two molybdenum disilicide turbine blades under centrifugal loads imposed by turbine rotation is presented. Molybdenum disilicide turbine blades fabricated by hot-pressing techniques withstood heat-shock conditions under blade centrifugal stresses up to 5350 pounds per square inch. Additional development is required before the heat-shock resistant properties of molybdenum disilicide are satisfactory for turbine-blade application.

Report presenting a pressure-distribution investigation in the high-speed tunnel of a wing-fuselage configuration as part of an NACA research program to determine effects of wing geometry on aerodynamic characteristics and to explore the nature of flow over the configuration. Measurements were made on a fuselage and wing-fuselage combination for a range of Mach numbers. Results regarding accuracy, figures of pressure distributions, pressure distributions on the wing and fuselage, results at several angles of attack, section loading characteristics, normal-force characteristics, pitching-moment characteristics, pressure-drag characteristics, and fuselage skin-friction drag are provided.

Report presenting a wind-tunnel investigation to determine the low-speed longitudinal and lateral control characteristics of a model with a triangular wing with NACA 65(06)-006.5 airfoil sections, aspect ratio 2.31, and constant-chord control surfaces. The values of the hinge-moment parameters were found to be of somewhat greater magnitude than would be expected on unswept wings with the same aspect ratio.

Report presenting a direct-connect altitude test chamber investigation of the combustion performance of a 28-inch-diameter ramjet engine with a can-type center pilot burner. Combustion-chamber configurations with three different flame holders were investigated at a simulated flight Mach number of 2.0 and several different altitudes.

Theoretical values of performance parameters for liquid hydrogen and liquid fluorine as a rocket propellant were calculated on the assumption of equilibrium composition during the expansion process for a wide range of fuel-oxidant and expansion ratios. The parameters included were specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ration of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity. The maximum value of specific impulse was 364.6 pound-seconds per pound for a chamber pressure of 300 pounds per square inch absolute (20.41 atm) and an exit pressure of 1 atmosphere.

Report presenting an investigation to determine the effects of pouring temperature and grain size on the uniformity of lives and initial failure times of groups of AMS 5385 gas turbine blades and to relate the individual lives of the blades to grain size. This is due to the fact that the uniformity of lift of cast alloy gas-turbine blades is generally unsatisfactory. Results regarding the metallurgical examination are provided.

Report presenting an experimental investigation using a 16-inch impulse-type supersonic-compressor rotor as a separate component, which obtained a maximum total-pressure ratio of 5.42 and an adiabatic efficiency of 0.76 at 101-percent design speed. The rotor could operate over a wide range of back pressures, but it did not obtain the design impulse condition. Results regarding the rotor-component investigation and stage investigation are provided.

Memorandum presenting an investigation in the 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.61 and 2.01 to determine the static longitudinal stability and control characteristics of a 1/16-scale model of the Douglas D-558-II research airplane. The results indicated a high degree of longitudinal stability that decreased slightly with increasing Mach number and lift coefficient.

A study investigated the effects of suction through porous leading-edge surfaces on the longitudinal aerodynamic characteristics of a 47.5 degree sweptback wing-fuselage configuration in the full-scale tunnel. The wing section normal to the quarter-chord line was NACA 64(sub 1)A112, the aspect ratio was 3.4, and the taper ratio was 0.51. Results regarding the basic wing characteristics and effect of area suction on the longitudinal characteristics are provided.

Report presenting a flight investigation of a small, all-movable tail to determine whether it is an effective longitudinal control for a cruciform, delta-wing missile at a range of Mach numbers from 0.67 to 1.81. The stability, control, hinge-moment, and drag characteristics are provided.