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.

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.

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.

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 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.

The significant findings of a theoretical study of column behavior in the plastic stress range are presented. When the behavior of a straight column is regarded as the limiting behavior of an imperfect column as the initial imperfection (lack of straightness) approaches zero, the departure from the straight configuration occurs at the tangent-modulus load. Without such a concept of the behavior of a straight column, one is led to the unrealistic conclusion that lateral deflection of the column can begin at any load between the tangent-modulus value and the Euler load, based on the original elastic modulus. A family of curves showing load against lateral deflection is presented for idealized h-section columns of various lengths and of various materials that have a systematic variation of their stress-strain curves.

"The formulas of subsonic and supersonic wing theory for source, doublet, and vortex distributions are reviewed and a systematic presentation is provided which relates these distributions to the pressure and to the vertical induced velocity in the plane of the wing. It is shown that care must be used in treating the singularities involved in the analysis and that the order of integration is not always reversible. Concepts suggested by the irreversibility of order of integration are shown to be useful in the inversion of singular integral equations when operational techniques are used. A number of examples are given to illustrate the methods presented, attention being directed to supersonic flight speed" (p. 1267).

"A lift-cancellation technique is presented for determining load distributions on thin wings at supersonic speeds. The loading on a wing having a prescribed plan form is expressed as the loading of a known related wing (such as a two-dimensional or triangular wing) minus the loading of an appropriate cancellation wing. The lift-cancellation technique can be used to find the loading on a large variety of wings. Applications to swept wings having curvilinear plan forms and to wings having reentrant side edges are indicated" (p. 65).

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.

"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).