Memorandum presenting an investigation of the dynamics of a turbine-propeller engine in the altitude wind tunnel employing the frequency-response technique for a range of pressure altitudes form 10,000 to 30,000 feet. The investigation showed that the dynamic responses generalized for pressure altitude over the range of frequencies investigated. Results regarding steady-state characteristics, the linearity investigation, and dynamic characteristics are provided.

From Introduction: "Presented in this paper are the results of an investigation of a semispan model of a delta wing with 60^o sweepback at the leading edge which was equipped with a large triangular control having an overhang balance mounted on a skewed hinge axis. The purpose of this investigation was to determine the aerodynamic characteristics of a delta wing with a control which was designed to provide aerodynamic balance at zero control deflection based on the span load distribution of reference 1."

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 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.

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.

Report presenting the damping-in-roll stability derivatives of a missile configuration and its components as determined experimentally and theoretically. The experimental damping derivative of the wing-body combination was found to be 67 percent of its theoretical value. Results are given for the wing-body combination, the tail-body combination, and the wing-tail-body combination.

"A method of measuring instantaneous flow rates of liquid propellants for rocket research is presented. The instrument investigated utilizes the principle of electromagnetic induction. An electromagnetic flowmeter was built, investigated, and satisfactorily placed in service to measure the rate of flow of an oxidant into a rocket" (p. 1).

"A principle formerly used in an instrument for cloud detection was further investigated to provide a simple and rapid means for measuring the liquid-water content of clouds at temperatures above and below freezing. The instrument consists of a small cylindrical element so operated at high surface temperatures that the impingement of cloud droplets creates a significant drop in the surface temperature. The instrument is sensitive to a wide range of liquid-water content and was calibrated at one set of fixed conditions against rotating multicylinder measurements. The limited conditions of the calibration Included an air temperature of 20 F, an air velocity of 175 miles per hour, and a surface temperature in clear air of 475 F" (p. 1).

Report presenting an analysis of a series of wing-body combinations in the 8-foot high-speed tunnel. The paper presents the results of an investigation of a wing-fuselage combination with a wing of unswept quarter-chord line, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section. Results regarding force and moment characteristics and wake and downwash characteristics are provided.

Report presenting a low-speed investigation in the stability tunnel to determine the effects of symmetrical deflection of half-delta tip controls on the damping in roll and yawing moment due to rolling of a model with triangular wings. Triangular wings have numerous aerodynamic advantages, but it is difficult to obtain adequate longitudinal and lateral control with acceptable control forces when using them. Results regarding the lift characteristics and rolling characteristics are provided.

Report presenting a wind-tunnel investigation from a Mach number range of 0.30 to 0.94 to determine the rolling characteristics of a three-winged free-flight type of test vehicle with untapered 45 degree sweptback wings with NACA 65A009 airfoil sections and 0.20-chord ailerons. Results regarding wing-tip helix angles, rolling-moment coefficient, and damping-in-roll coefficients are provided.

Report discussing an investigation of the effect of sweepback angle on wing-fuselage characteristics at a subsonic and a supersonic Mach number. Lift, drag, and pitching-moment coefficients, downwash-angle, and total-pressure measurements are all provided.

Report presenting testing of wing-body combinations incorporating several wing plan forms of theoretical interest at Mach numbers of 1.62, 1.93, and 2.41 in the supersonic tunnel. One triangular, one arrow, and tow diamond plan forms were tested. Results regarding minimum drag, lift-curve slope, center-of-pressure positions, drag due to lift, and lift-drag ratios are provided.

Component data on the J35-A-23 compressor and two-stage turbine were used to determine the problems in matching the two units for operation in a turbojet engine. Possible operating regions were determined and an equilibrium operating line was also determined for the assumed conditions of zero flight speed and a jet nozzle area approximately 5.5 percent greater than the wide-open nozzle area.

Report presenting an investigation in the 300 mph tunnel to determine the low-speed stability and control characteristics and the jet-engine duct-inlet pressure recovery characteristics of a model of the Edo 142 hydro-ski research airplane. Results regarding the longitudinal stability and control, stall-control devices, alighting gear, lateral stability, directional control, lateral control, and duct pressure recovery are provided.

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.

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 discussing the results of an investigation to determine the stability and control characteristics of a flying model of an unswept-wing vertically rising airplane. Information about stabilization, maneuverability, rolling motions, and landings is provided.

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 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 method is described for determining the "displacement surface" of known three-dimensional compressible boundary-layer flow in terms of the mass-flow defects associated with the profiles of the two velocity components parallel to the surface. The result is a generalization of the plane flow concept of displacement thickness introduced in order to describe how a thin boundary layer distorts the outer nonviscous flow. Numerical values are found for the known three-dimensional boundary-layer flow about a cone at a small angle of attack to a supersonic stream" (p. 367).

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 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.