A flight investigation in natural icing conditions was conducted to determine the effect of inlet ice formations on the performance of axial-flow turbojet engines. The results are presented for icing conditions ranging from a liquid-water content of 0.1 to 0.9 gram per cubic meter and water-droplet size from 10 to 27 microns at ambient-air temperature from 13 to 26 degrees F. The data show time histories of jet thrust, air flow, tail-pipe temperature, compressor efficiency, and icing parameters for each icing encounter. The effect of inlet-guide-vane icing was isolated and shown to account for approximately one-half the total reduction in performance caused by inlet icing.

Investigations were conducted to determine effectiveness of refrigerants in increasing thrust of turbojet engines. Mixtures of water an alcohol were injected for a range of total flows up to 2.2 lb/sec. Kerosene was injected into inlets covering a range of injected flows up to approximately 30% of normal engine fuel flow. Injection of 2.0 lb/sec of water alone produced an increase in thrust of 35.8% of rate engine conditions and kerosene produced a negligible increase in thrust. Carbon dioxide increased thrust 23.5 percent.

Report presenting the results of pressure-distribution tests to determine the effects of compressibility on the characteristics of the NACA 66,2-215, 66,2-015, 65(216)-418, 16-212, and 23015 airfoil sections. Schileren photographs of the air flow and data on the wake characteristics was also obtained.

Report presenting testing in the 300 mph tunnel of a model with a sweptback vee tail and a sweptback wing to determine its low-speed stability and control characteristics. The results are compared to testing with the same tail panel with zero dihedral on the same wing-fuselage combination. The longitudinal stability characteristics, downwash at the tail, longitudinal control characteristics, lateral stability characteristics, and rudder control characteristics are provided.

Memorandum presenting an investigation of two annular diffusers of different conical angles of expansion but constant outer diameters with rotating flow behind a fan. The performance characteristics are determined and the rotational-kinetic-energy effects on the overall energy transformation are observed over a range of inlet mach numbers from 0.1 to 0.44 and angles of flow up to 28 degrees.

Report discussing flow surveys made of several nozzles using two 2-dimensional steps at Mach number 6.98. Results regarding wall-pressure surveys, disturbance patterns in expansion, total-pressure survey, temperature recovery, and general nozzle characteristics are provided.

Report presenting an investigation of the pressure distribution over a rectangular wing with a 9-percent-thick symmetrical circular-arc section and a 30-percent-chord trailing-edge flap. Results are given for pressure distributions, Schileren and liquid-film studies, and wing section characteristics are provided.

Report presenting testing of a full-scale, semispan, horizontal tail surface for a jet-propelled fighter airplane in the 16-foot high-speed tunnel to determine the variation of the chordwise and spanwise pressure distributions with Mach number. Surface irregularities were found to cause appreciable distortion of the pressure distribution. Results regarding chordwise distributions, spanwise distribution, effect of Mach number on root bending moment, and estimated critical Mach numbers are provided.

Report presenting the use of wall perforations on supersonic diffusers to avoid the internal contraction-ratio limitation. Experimental results on a preliminary model of a perforated diffuser at Mach number 1.85 are provided. A theoretical discussion of the flow coefficients and the size and spacing of the perforations are included.

Report presenting an investigation in the 300 mph 7- by 10-foot tunnel to determine what modifications could be made to conventional bomb bays to reduce the tumbling difficulties experienced with light-weight bombs. The investigation indicated that there is a definite region of reversed flow inside the bomb bay which must be weakened or destroyed if good drops are to be obtained.

Report presenting an experimental investigation of a submerged air inlet incorporating a cascade of airfoils for turning and diffusing the entering air. Variables associated with submerged air inlets and airfoil-cascade designs were considered, including changes to the ramp plan form and angle for the submerged inlet and the cascade-axis inclination, cascade-blade angle, solidity, and inclination of the center line of the duct for the cascade.

Report presenting measurements of the longitudinal stability and control characteristics of a canard airplane configuration using the wing-flow method. The investigation included measurements of lift, pitching moment, and rolling moment of the semispan model with control settings between several different degrees. The experimental data are presented in summarized or abridged form and calculated trim curves are presented for various flight loading conditions.

Report presenting drag coefficients determined by the accelerometer method for the Bell X-1 airplane with 8-percent-thick wing and 6-percent-thick tail in power-off flight over a range of Mach numbers and lift coefficients. Results regarding the variation of computed lift and drag coefficients, variation of lift coefficient with Mach number, and effect of Mach number on lift-drag ratio are provided.

Report presenting visual observations and flow analyses made of annular liquid flow with cocurrent air flow in 2- and 4-inch-diameter horizontal transparent tubes. The experiments occurred over a range of air mass velocities, air temperatures, and Reynolds numbers. Results regarding the velocity and thickness of liquid films, description of water-film disturbances, effect of flow variables on liquid-film characteristics, and relation between disturbances and flow conditions are provided.

Report presenting a comparison of the calculated response characteristics corresponding to the maximum maneuver of a variable-incidence, a canard, and a conventional tail-aft-control, beam-rider, guided missile. All the configurations were designed to be the same except for the effects of changes in lift ratio. Results regarding limited control-surface deflection, limited angle of attack of the critical surface, servo energy, surface-deflection interference, and size of surfaces are provided.

Report presenting measurements of pressure made over the chord of a swept-wing model at four stations along the span by the NACA wing-flow method. The model was an untapered 45 degree sweptback wing of aspect ratio 3.5 with 2-inch-chord NACA 65-210 airfoil sections normal to the leading edge. Results regarding the chordwise pressure distributions and spanwise distributions of section lift, drag, and pitching moment.

Report presenting an investigation of zero-lift drag of a fin-stabilized wing-body combination made at high-subsonic and supersonic speeds in a range of Reynolds numbers. The data are presented with that from a wingless body and similar winged body with a slightly different ratio of body frontal area to wing area. Results regarding total drag and wing-plus-interference drag are provided.

Report of testing on an untapered 35-degree sweptback airfoil-flap model, representative of a wing or tail surface, with several 1/4-chord full-span flaps differing in aerodynamic balance. A plain flap, a horn-balanced flap, and a beveled-trailing-edge flap were compared to a flap that had a 31-percent-flap-chord overhang balance. Information about lift, pitching-moment, and hinge-moment characteristics is provided.

"Values of total drag coefficient were measured for four round-nosed bodies of revolution in free flight at Mach numbers from 0.6 to 1.5 and Reynolds numbers from 10 x 10(6) to 50 x 10(6). The bodies were designed by rounding off the sharp, fineness-ratio-3.56 nose of a previously tested configuration. The nose radii tested were 27.4, 38.7, 80.6, and 100 percent of the maximum body radius and corresponded to values of 0.075, 0.150, 0.650, and 1.000, respectively, for the ratio of nose-sphere frontal area to body frontal area" (p. 1).

Memorandum presenting the pressure recovery, mass flow, and drag of a twin-scoop, side-inlet-body combination measured at Mach number 1.4 and 1.7. The inlet was located on a body having an ogival nose followed by a cylindrical section and a total fineness ratio of 5.

Memorandum presenting a systematic study to determine the effect of molecular structure on the flammability limits of pure hydrocarbon-air mixtures at reduced pressures and room temperature. This report presents results obtained for 17 pure normal paraffins, branched paraffins, and mono-olefins. Results regarding experimental variables and experimental observations are provided.

Memorandum presenting an investigation to evaluate the effect of Reynolds number and Mach number on the aerodynamic characteristics of a horizontal tail of aspect ratio 3 equipped with a plain, sealed, full-span elevator. The line joining the quarter-chord points of the airfoil sections was swept back 45 degrees and the sections perpendicular to this line were the NACA 64A010. Results regarding the effect of Reynolds number and effects of leading-edge roughness and elevator-nose seal are provided.

Report presenting a theoretical analysis of a supersonic canard missile configuration to show the means that might be used to improve its dynamic performance characteristics. The analysis was conducted by using the best available estimates of aerodynamic and airframe parameters. Results regarding missile longitudinal performance, selection of rate factor, angle of attack and normal acceleration, frequency response, pole plots, and tip control are provided.

Memorandum presenting the pressure recovery, mass flow, and axial force of four bodies with nose inlets measured at Mach numbers between 1.4 and 2.0 and angles of attack of 0, 3, 6, and 9 degrees. The drag coefficients of axially symmetric diffusers operating at the maximum mass-flow rates were calculated from schileren photographs of the head shock waves and frictional drag considerations. Results regarding open-nose diffusers and conical-shock diffusers are provided.