Report presenting the results of an investigation to determine the effects of a small jet of air exhausting from the nose of an elliptical body of revolution upon boundary-layer transition and the viscous, pressure, and total drag of the forebody at three body stations at Mach number 1.62. The jet effects on body pressure, pressure variations, boundary-layer transition, and total drag are provided.

Report presenting an investigation of the results at high Reynolds numbers and low Mach numbers to determine the maximum-lift and stalling characteristics of an aspect-ratio-4 trapezoidal wing with 10-percent-thick, circular-arc airfoil sections. Testing occurred measurements of lift, drag, and pitching-moment coefficients of the basic wing and of the wing with 0.20-chord droop-nose and rear flaps deflected alone and in combination with one another.

Report presenting an investigation in the low-turbulence pressure tunnel to determine the effects of Mach and Reynolds number on the maximum lift characteristics of the NACA 65-006, 64-009, 64-210, and 64(sub 2)-215 airfoil sections in smooth and leading-edge roughness conditions. A range of Mach and Reynolds numbers were explored.

Report presenting a study of the lift and drag characteristics of a number of airfoil sections at supercritical Mach numbers as determined from wind-tunnel tests.

A theoretical investigation is made of the loads and motions in water-landing impacts of wide prismatic V-bottom seaplanes for constant partial wing-lift conditions where the resultant velocity of the seaplane is normal to the keel. An approximate method is given for applying the results of this investigation to the more general case of oblique impact. The increase in vertical hydrodynamic load factor due to wing-lift reduction is shown to be approximately 133 percent of the decrease in air load.

Note presenting smooth-water landing tests of a prismatic model with an angle of dead rise of 22.5 degrees as part of a landing investigation being conducted in the impact basin to determine the distribution of water pressure on seaplanes. Landings were made for a variety of beam-loading coefficients, fixed trims, and range of initial flight-path angles. The experimental wave rise, peak pressures, and pressure distributions are found to be in fair agreement with the predictions of the available theory, but better arrangement is obtained by modification of the theory.

Report presenting an investigation in the stability tunnel to determine the effect of high-lift devices on the low-speed static-lateral-stability derivatives of a 45 degree sweptback wing of aspect ratio 4.0 and taper ratio 0.6. Comparisons between the increments in the static-lateral-stability derivatives due to flap deflection obtained from experiment and the increments evaluated by a single sweep theory is also made. Results regarding the presentation of results, longitudinal stability characteristics, static lateral stability characteristics, and comparison of calculated and measured values are provided.

A theory for the side force, rolling moment, yawing moment, and pressure distribution during yawed landings and planing of seaplanes was developed. For the special case of the straight-sided wedge without chine immersion, the results of the theoretical analysis are presented in the form of generalized curves covering all step landing conditions. Experimental impact and planing data are presented for a prismatic wedge having an angle of dead rise of 22.5 degrees and are shown to be in reasonable agreement with the theoretical predictions.

Report presenting the constant-temperature hot-wire anemometer amplifier and accessories have been developed to provide an instrument with wide frequency response, good stability, and ease of operation. Techniques are described using the equipment to study periodic phenomena such as surge, rotating stall, and wake surveys in centrifugal- and axial-flow compressors.

Note presenting the first-order solution for the laminar compressible boundary-layer flow over a flat plate at constant wall temperature. The effect of slip at the wall as well as the interaction between the boundary-layer flow and the outer stream flow are taken into consideration.

Note presenting an analysis of the laminar boundary-layer flow about a circular cone at large angles of attack to a supersonic stream in the plane of symmetry by a method applicable in general to the flow about conical bodies. Velocity profiles at the bottom of the cone indicated that the expected tendency of the boundary layer to become thinner on the under side of the cone as the angle of attack is increased.

Report presenting a modification of the passage contour of a 48-inch centrifugal compressor modified by changing the shape of the hub to control deceleration rates along the blade surfaces in order to improve the internal efficiency of the impeller. Results regarding the overall performance, comparison of internal-flow characteristics of three impeller configurations at design flow rate, and variation of internal-flow characteristics of modified-hub impeller with weight flow are provided.

Report presenting a study of several aspects of transonic flow around the forward portions of wedge profiles by means of interferometry. Measurements were made of the two kinds of flow pattern that occur at the leading edge of a wedge at an angle of attack. Results regarding the flow at leading edge, flow around the corner, method of characteristics, drag coefficient of the wedge at 14.5 degree semiangle, and conditions at bases of shock waves are provided.

Report presenting an investigation to provide a basis for the design of combination probes intended to survey the static and total pressure and direction of flow with special reference to subsonic turbo-machine testing. Static-pressure probes, yaw-element probes, claw-type yaw probes, and combination probes were tested in an 8-inch-diameter calibration tunnel. The factors that determine the sensitivity of claw-type yaw probes were determined from this test.

Note describing a method of engine simulation involving the use of an electronic analog computer in the simulation of controlled aircraft-engine performance. The equations used in developing the method of simulating the dynamics of gas-turbine engines are derived in general form from engine functional relations.

Report presenting a description of a low-cost interferometer that is easy to adjust and has a large field of view. The instrument uses small diffraction gratings to produce and recombine separate beams of light. The usual two-parabolic-mirror schileren system can be converted inexpensivley to a diffraction-grating interferometer.

Report presenting the effect of a finite trailing-edge thickness on the pressure drag of rectangular and delta wings with truncated diamond-shaped airfoil sections with a given thickness ratio studied for supersonic Mach numbers. Results regarding the effect of wing profile geometry, result of the solution of equations, elimination of base pressure as a parameter, ratio of drag coefficients, pressures inside and outside the Mach cone, and effect of changes in aspect ratio are provided.

From Introduction: "It is shown in the body of this report that the solution to the error problem depends upon a more or less arbitrary definition, the only criterion as to the choice of the definition being the usefulness of the solution to which it leads. In this respect, it may be said of the method derived herein that it is not difficult to apply and appears to lead reasonable values of the errors."

Second report in a series presenting torsion testing on aluminum-alloy stiffened circular cylinders. The cylinders were similar to those from the first test with the exception of the wall thickness. Results regarding the action before buckling, buckling of curved panels, tension-field action, and ultimate torsional strengths are provided.

Note presenting normal-acceleration and airspeed data obtained for one type of twin-engine transport airplane in commercial operations in order to determine the gust and gust-load experiences of the airplane. Results regarding acceleration experience, gust experience, seasonal effects, and effect of special operating restriction are provided.

Report presenting an investigation of three-dimensional, incompressible, nonviscous, absolute irrotational fluid motion is determined for flow through rotating axial-flow passages bounded by straight blades of finite spacing and infinite axial length lying on meridional planes. Solutions are obtained for five passages with varying blade spacing and hub-tip ratio. The results are presented in such a manner as to apply for all ratios of axial velocity to passage tip speed.

Note presenting the general equations governing the fixed-trim water landing of a straight-keel seaplane with a hull of arbitrary constant cross section in such a form that the landing motions and loads are expressed in terms of the steady planing characteristics of the seaplane.

A general solution, based on the classical buckling criterion, is given for the problem of buckling of low arches under a lateral loading acting toward the center of curvature. For a sinusoidal arch under sinusoidal loading, the critical load can be expressed exactly as a simple function of the beam dimension parameters. For other arch shapes and load distributions, approximate values of the critical load can be obtained by summing a few terms of a rapidly converging Fourier series.

An experimental investigation was conducted to obtain performance data on bearings of length-diameter ratios of 1, 1/2, and 1/4 for comparison with theoretical curves. A 1.375-inch-diameter bearing was tested at speeds up to 6000 rpm and with unit loads from 0 to 900 pounds per square inch. Experimental data for eccentricity ratio and friction followed single lines when plotted against a theoretically derived capacity number, which is equal to Sommerfeld number times the square of the length-diameter ratio.