Report of an investigation to determine the effect of surface roughness on the performance of a 23 degree conical diffusers with 2:1 ratio of exit to inlet area and a constant-area tail pipe. Information about the pressure survey results, including total-pressure-loss coefficient, diffuser effectiveness, and boundary-layer profiles is provided.

Memorandum presenting an investigation at Mach numbers of 1.41, 1.62, and 1.96 to determine the effects of airfoil section and wing plan form on the pressures acting on the base of blunt-trailing-edge wings operating through an angle-of-attack range. The investigation included two groups of untapered wings of aspect ratio 2.7, with one group being unswept and the other with 45 degrees of sweepback. Results regarding the effects of wing location and body size, spanwise variations of base pressures, variations of average base pressure coefficients with angle of attack and wing section, and effects of plan form are provided.

A slug of air-saturated distilled water was circulated for 317 hours at a velocity of 15 feet per second in an AISI 347 stainless-steel toroid with a wall temperature of 500 F and a 30 F difference in temperature between the hot and cold sections. The depth of corrosion layer was 0.001 inch (0.028 in./yr) in the hot sector and 0.0007 inch (0.019 in./yr) in the cold sector; no mass transfer was observed. The results of gas,water,and X-ray diffraction analyses are given together with photomicrographs of sections taken from the hot and cold sections of the specimen.

Report presenting an investigation of inlets utilizing two-dimensional compression wedges mounted normal to the fuselage surface with ram-type scoops for partial removal of the boundary layer. Two compression-wedge angles were included to simulate fixed positions of a variable-geometry configuration. Results regarding supersonic performance characteristics and subsonic and take-off performance characteristics are provided.

Report presenting the results of a free-flight investigation to determine the drag of circular, finite-length cylinders for a range of Mach numbers. For supersonic speeds, the drag of circular cylinders was found to be largely independent of fineness ratio and Reynolds number.

Memorandum presenting an investigation of the influence of blade-row geometry on secondary flows in a two-dimensional cascade by varying independently stagger angle, aspect ratio, solidity, and angle of attack and by providing blade fillets. Stagger angle and aspect ratio had no appreciable effect on this secondary flow, whereas solidity and angle of attack did affect the flow patterns indicating the turning as a major parameter.

Report presenting an investigation of the applicability of a finite-step method to the calculation of subsonic spanwise load distribution, lift-curve slope, lateral center of pressure, and aerodynamic center of unusual plan forms. The 20-step method was found to generally overestimate the amount of loading at the wing tip, but the lift-curve slope, lateral center of pressure, aerodynamic center, and loading shape generally agreed with lifting-surface results.

A set of modified NACA 5509-34 rotor and stator blades was investigated with rough-machine, hand-filed, and highly polished surface finishes over a range of weight flows at six equivalent tip speeds from 672 to 1092 feet per second to determine the effect of blade-surface finish on the performance of a single-stage axial-flow compressor. Surface-finish effects decreased with increasing compressor speed and with decreasing flow at a given speed. In general, finishing blade surfaces below the roughness that may be considered aerodynamically smooth on the basis of an admissible-roughness formula will have no effect on compressor performance.

From Summary: "A study of the available transonic Mach number data on low-lift buffeting, wing dropping, and changes in the angles of zero lift for symmetrical airfoils indicates that these phenomena are allied and are probably the result of shock-induced separation. The study has indicated that there are combinations of airfoil-thickness ratio, aspect ratio, and sweep which may allow flight through the transonic speed range without experiencing buffet or wing drop at low lift."

Memorandum presenting steady-state and transient characteristics of the J34-WE-32 turbojet engine with electronic power regulator as obtained in the altitude wind tunnel to determine the effects of engine and control limits on the performance. Limits on the fuel valve and exhaust nozzle area influence any schedule of speed and temperature. Results regarding the effect of limits on operating schedule, effect of altitude on safe operating range, effect of minimum fuel flow settings on transient performance, and some potential problems are provided.

Report presenting testing of two rocket-propelled research models to determine the effect of the intersection of thin aerodynamic surfaces and the effect of moderate sweepback of thick aerodynamic surfaces on low-lift buffeting. Results regarding trim changes and drag are also provided. It was discovered that low-lift buffeting may be induced at high subsonic speeds by interference due to the intersection of thin aerodynamic surfaces.

Some measurements of the effects of rocket-motor operation on base pressure were obtained incidental to other research on some bodies in free flight. These data are presented and qualitatively analyzed. The analysis indicates that jet effects on drag are of sufficient importance to deserve consideration in the design of jet motor nozzles, especially for aircraft and missiles where the thrust and drag are of the same order of magnitude. The base-pressure changes induced by the jet should be considered in the structural design of the outer body skin on the aft portion of fuselages containing jets. (author).

Report presenting an investigation of the low-speed longitudinal, lateral, and directional stability characteristics if a 1/4-scale model of a preliminary Bell X-5 airplane design with modifications to the basic model configuration. Results regarding the dive brakes, trailing-edge fillets, extended wing tips, fences, wing incidence, and fins are provided.

Various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes from sea level to 50,000 feet are presented. The analytical results indicate that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. The constant-speed second stage could be either a mixed-flow rotary compressor or a piston-type compressor. A variable-area turbine nozzle is shown to be unnecessary for cruising operation of the engine.

Report presenting an investigation to determine the damping in yaw and static directional stability characteristics for a flat-fuselage model with its major cross-sectional axis either horizontal or vertical, for a flat-fuselage model with its major axis horizontal in combination with a 45 degree sweptback wing, and for a canard model with a triangular control surface and 45 degree sweptback wing.

Report presenting an experimental investigation of the flow field downstream of a canard-type control surface and in the vicinity of a symmetrical body in the 8- by 6-foot supersonic tunnel at Mach numbers of 1.8 and 2.0. The results indicated severe total pressure losses and large flow deflections in the control surface wake.

Report presenting pressure distributions and Schileren photographs of the flow around a 10-percent-thick diamond airfoil at zero lift in two-dimensional closed, slotted, and open-throat tunnels. Results regarding the effect of slot area ratio and effect of slot spacing are provided.

"A preliminary investigation has been made in order to determine the static and dynamic longitudinal stability characteristics and the force characteristics of a Grunberg hydrofoil system comprising a main lifting hydrofoil and planing-surface stabilizers. The tests showed that a rearward movement of the center of gravity decreased the static and dynamic stability but increased the lift-drag ratio. In smooth water, adequate static stability was observed for all conditions tested" (p. 1).

"An investigation of the use of solid fences installed on the side walls of a supersonic wind tunnel to retard the development of transverse flow and thus to increase the uniformity of the side-wall boundary layer is reported. Beneficial results were obtained with fences which had depths of the order of the boundary-layer displacement thickness and which followed potential-flow streamlines through the nozzle. Reduction of the number of fences on each side wall from four to two eliminated their effectiveness" (p. 1).

Memorandum presenting a small-scale investigation of the effects of full-span and partial-span leading-edge flaps on the aerodynamic characteristics of a sweptback wing in the 7- by 10-foot tunnel over a Mach number range of 0.70 to 1.10. Lift, drag, pitching moment, and bending moment were obtained for the basic wing and for the wing with full-span and partial-span leading-edge-flap deflections of approximately 3, 6, and 9 degrees.

A general discussion of the air-inlet problem is presented. Recently obtained drag and pressure-recovery data for transonic-type nose, scoop, and wing-root inlets are summarized. Preliminary results concerning the performance of the sharp-edged supersonic-type inlets at transonic and subsonic speeds also are given.

Report presenting an experimental investigation to determine the performance of twin-scoop side inlets located on the fuselage of a proposed aircraft in a region of large boundary-layer thickness. Inlet configurations with subsonic and supersonic cowlings which utilized two-dimensional compression ramps and ram-type scoops for boundary-layer-removal systems were investigated at several Mach number ranges. Results regarding supersonic Mach number range, angle of attack, subsonic Mach number, and static conditions are provided.

Report presenting an investigation of the overall performance of a 20-inch-tip-diameter 10-stage compressor as the initial step to examine the problems encountered in an axial-flow compressor with a high pressure ratio per stage. The investigation was carried out over a range of weight flows and percentages of the design speed. Results regarding the part-speed efficiency, surge characteristics, overspeed characteristics, compressor discharge Mach number, and stage characteristics are provided.

Report presenting the results of a theoretical and experimental study of ramjet diffuser flow pulsing, commonly referred to as a buzz condition, with and without combustion. The acoustical resonance properties of ram jets are an important factor in establishing the frequency of diffuser flow pulsations.