Report presenting an investigation of the pressure distribution on the full-span droop-nose flap of a wing with the leading edge swept back 47.5 degrees and symmetrical circular-arc airfoil sections. Flap pressure distributions were obtained for the base configuration and various deflections of the full-span droop-nose flap and other flap deflection combinations. Information regarding the flow and section characteristics, spanwise loading parameters, center-of-pressure variation, and flap normal-force and hinge-moment coefficients is provided.

Memorandum presenting an investigation of the drag and pressure distribution on a body of revolution of fineness ratio 12 as measured by the free-fall method. Analysis of the results has provided knowledge of the mechanism of the abrupt drag rise which occurs near the speed of sound, and demonstrates that the theoretical method described in a previous report satisfactorily predicts the shape of the measured pressure distributions at low supersonic speeds.

"Free-flight tests have been made to determine the zero-lift drag of several configurations of the XAAM-N-2 pilotless aircraft. Base-pressure measurements were also obtained for some of the configurations. The results show that increasing the wing-thickness ratio from 4 to 6 percent increased the wing drag by about 100 percent at M = 1.3 and by about 30 percent at M = 1.8. Increasing the nose fineness ratio from 5.00 to 6.25 reduced the drag coefficient of the wingless models a maximum of about 0.030 (10 percent) at M = 2.0" (p. 1).

Report presenting an investigation to determine the effects of flap size and location on an unswept semispan wing in combination with a half-fuselage. The wing had an aspect ratio of 2.5, a taper ratio of 0.625, and 6-percent-thick modified double-wedge airfoil sections. Results regarding wing characteristics and flap characteristics are provided.

Report presenting low-speed tests of an airfoil model with a freely hinged flap attached to spoilers which passed through slots in the airfoil ahead of the hinge line. Testing indicated that buzz is not caused simply by buffeting of a flap by separated flow. Results regarding the oscillations experienced with the spoiler and flap in several positions are provided.

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.

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.

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 base pressures measured in flight on fin-stabilized bodies of revolution with and without rocket chambers and a converging afterbody at a range of Mach numbers. Pressures were found to be higher over the center portion of the bases of models with rocket chambers than edge pressures, while center base pressures on models without rocket chambers were lower than edge pressures.

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).

From Summary: "A rudder bulb was installed on the trailing edge of the rudder of the Bell X-1 airplane having the 8-percent-thick wing and 6-percent-thick tail. Several flights were made to investigate the effects of the bulb on the snaking oscillation at Mach numbers between 0.75 and 1.0. It was found that the rudder bulb had no noticeable effect on the snaking oscillation over the Mach number range tested."

"A wind-tunnel investigation of a 0.049-scale model of the Boeing XB-52 airplane was made at Mach numbers from 0.30 to 0.925 and at corresponding Reynolds numbers from about 2.3 x 10(exp 6) to 4.3 x 10(exp 6). The results of the investigation indicate satisfactory static longitudinal stability throughout the test Mach-number range and some loss in tail effectiveness beginning at about 0.80 Mach number. A comparison of the results of these tests with those of the same model in the Boeing Airplane Company's wind tunnel showed close agreement of lift- and drag-divergence Mach numbers. Slight differences were observed in tail effectiveness and the position of the stick-fixed neutral point."

Memorandum presenting a wind-tunnel investigation of the low-speed, static, lateral and directional characteristics of a model of an early design of the X-3 airplane with the wing flaps neutral and deflected. The model utilized a wing with an aspect ratio of 3.01, a 4.5-percent-thick hexagonal section, and a taper ratio of 0.4. Results regarding lateral stability and control with the flaps neutral, with the flaps fully deflected, with miscellaneous additions to the complete model, directional stability and control with the flaps neutral, with the flap fully deflected, with miscellaneous additions to the complete model, and oscillating rolling moments are provided.

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."

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.

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.

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.

Memorandum presenting an investigation to determine the effects of scale and compressibility on the forces, moments, and pressure distribution on a wing with an aspect ratio of 3 and a taper ratio of 0.5. Lift, drag, and pitching-moment data and the chordwise distribution of static pressure at seven spanwise stations are presented for several sets of Reynolds and Mach numbers. The results indicated that for all Mach and Reynolds numbers in the test range, no apparently flow separation existed near the leading edge of the wing for lift coefficients less than 0.3.

Report presenting an investigation to determine the low-speed longitudinal characteristics of an aspect ratio 4 triangular wing alone and in combination with a fuselage, vertical tail, and horizontal tail. The complete model consisted of a wing with a fuselage of fineness ratio 12.5, a thin, triangular, vertical tail, and two thin, unswept, all-movable horizontal tails of two different aspect ratios.

Combustion-chamber performance characteristics of a Python turbine-propeller engine were determined from investigation of a complete engine over a range of engine speeds and shaft horsepowers at simulated altitudes. Results indicated the effect of engine operating conditions and altitude on combustion efficiency and combustion-chamber total pressure losses. Performance of this vaporizing type combustion chamber was also compared with several atomizing type combustion chambers.

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.

Report presenting an investigation at a Mach number of 1.24 to determine the distribution of lift, drag, and pitching moment between the wing and fuselage of a scale semispan model of the Bell X-5 airplane. Lift, drag, pitching moments, and wing bending moments were obtained for various angles of attack for 40 through 60 degrees sweptback duralumin wings in the presence of, but detached from, the fuselage.

Paper using the Bernoulli equation for nonsteady flow to derive formulas for propeller lift and thrust distribution in terms of wake-survey measurements of stagnation pressure rise through the propeller. Lift distributions and overall values of thrust from wake survey were compared with direct measurements of those values.

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.