Report presenting a study of the finite-span effects on the local loading characteristics of two sweptback wings at low speed in order to provide some information about the usefulness of two-dimensional section data and span-loading theory for determining the section characteristics of a swept wing. At low values of lift coefficient, the finite-span effects were restricted to regions of the wing close to the root and tip. Results regarding the local pressure-distribution comparisons, local lift-curve comparisons, and evaluation of surface-loading procedure are provided.

Note presenting a solution to second order in thickness derived for harmonically oscillating two-dimensional airfoils in supersonic flow. For slow oscillations of an arbitrary profile, the result is found as a series including the third power of frequency.

Report presenting the potential of the linearized flow for a lifting-line propeller of arbitrary circulation distribution at subsonic advance as derived in cylindrical harmonics. From the potential the induced angle at the lifting line is obtained.

Report presenting the velocity potential for a triangular wing with subsonic leading edges experiencing harmonic deformations in supersonic flow. The oscillations considered are such that the amplitude of wing distortion can be represented by a general quadratic expression for a surface.

Report presenting flight experiments with a freely falling model to observe the effects of steady rolling on the pitching and yawing motions of a body-tail combination. Steady rolling introduces yawing moments into the pitch oscillations and pitching motions into the yaw oscillations. Results regarding the experimental effects of steady-roll on no-roll natural frequencies, comparison of measured and experimental effects of steady rolling on the no-roll natural frequencies, and effects of roll as applied to the design of missiles are provided.

Report presenting a method for estimating the effect of blade-thickness taper on the inlet axial-velocity distribution of an entrance rotor-blade row with an axial inlet, and the influence of this velocity distribution on the alignment of the rotor blade for zero effective angle of attack. The method is developed for compressible and incompressible nonviscous fluids, and results are presented for incompressible flow into a plane, two dimensional cascade and for compressible flow into an entrance rotor-blade row with tapered blades.

Report presenting one-dimensional, steady-state, compressible, viscous flow relations which permit the determination of flow conditions at any radial position in a ducted helicopter blade. The relations are required for estimating the performance of proposed helicopter jet-propulsion systems which involve ducting air or gases through the blade from root to tip.

Note presenting a survey of the 1200 degrees Celsius isothermal sections of the iron-nickel-molybdenum and the cobalt-iron-molybdenum ternary systems. The phases occurring in the systems were identified by means of x-ray diffraction and by etching methods, and the phase boundaries at 1200 degrees Celsius were determined microscopically, using the disappearing phase method with quenched specimens. Results regarding the specific phases and phase diagrams are provided.

Report presenting a perturbation method for the calculation of velocity and temperature profiles and skin-friction and heat-transfer characteristics for two-dimensional, compressible laminar boundary layers with heat transfer and a small arbitrary pressure gradient is presented. The combined effects of heat transfer and pressure gradient on boundary-layer characteristics are demonstrated by applying the results of the analysis to two representative wings.

Report presenting calculation studies to evaluate the influence that wing bending flexibility has on the structural response to gusts for three twin-engine transports and one four-engine bomber. The manner in which dynamic response factors for acceleration and bending moment vary with different assumed airplane operational factors is shown.

Note presenting a summary of all phases of an investigation of fretting corrosion that has been conducted over a period of several years. Part I describes a test machine for measuring fretting damage under controlled experimental conditions. Part II presents data for mild steel fretted against itself, with a number of characteristics taken into consideration. Part III suggest a mechanism for the fretting process.

From Introduction: "In the present paper, an analysis of the power-off landing maneuver is presented in which an attempt is made to consider both the aerodynamic characteristics of the airplane and the human capabilities of the pilot. In this paper, the type of pilot judgment considered is that of a pilot with previous flight experience, although not necessarily flight experience in any particular airplane under discussion."

Report presenting calculations of rotational-noise and vortex-noise levels at a distance of 300 feet for engine ratings of 1000 to 10,000 horsepower for a large number of propellers in static operation. The results are presented in chart and table form for rapid estimation of the noise levels and spectrums in a range of tip Mach numbers. Results regarding tip Mach number, number of blades, and power loading are provided.

Report presenting direct-reading design charts for 24S-T3 aluminum-alloy flat compression panels with longitudinal formed hat-section stiffeners. The charts make it possible to directly determine the stress and all panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel. Results regarding simple compression, combined compression and bending, and combined compression, bending, and shear are provided.

Note presenting a method for the rapid determination of design velocity diagrams of turbine stages within specified aerodynamic limits. The method is presented in both chart and tabular form.

From Summary: "An application of the method of characteristics is presented which affords a means for determining the surface pressures for a class of two-dimensional airfoils of given nose shape and arbitrary rear part in a sonic or supersonic stream if surface pressure data are given for one member of the class. For engineering purposes, the method of characteristics may be replaced by a simple application of Prandtl-Meyer flow concepts. An explanation of the nonlinear force characteristics of two-dimensional airfoils at transonic speeds is presented on the basis of sensitivity of these flows to changes in geometry and angle of attack."

Static yawing moments and some instantaneous yawing moments are presented through a range of angle of attack at zero sideslip angle for a plain fuselage model having a sharp conical nose and for the fuselage with several nose modifications, one of which consisted of a ring located at different stations along the nose. Some circumferential pressure measurements at one station on the body at several angles of attack are also presented.

From Introduction: "The results presented herein were calculated for a symmetrical diamond airfoil at zero angle of attack for a range of airfoil-thickness ratios from 0.02 to 0.10, pressure altitude from sea level to 45,000 feet, and free-stream static temperatures to -.40^o F."

"Wake development behind circular cylinders at Reynolds numbers from 40 to 10,000 was investigated in a low-speed wind tunnel. Standard hotwire techniques were used to study the velocity fluctuations. The Reynolds number range of periodic vortex shedding is divided into two distinct subranges. At R = 40 to 150, called the stable range, regular vortex streets are formed and no turbulent motion is developed" (p. 1).

Report presenting an investigation of the effect of processing variables on the properties of sintered, wrought molybdenum. The amount of swaging, recrystallization, and stress-relieving were considered.

Report presenting an iteration method for solving the laminar-boundary-layer equations for compressible flow in the absence of a pressure gradient when the temperature variation of all the fluid thermal properties is considered. Results in regard to skin friction and heat-transfer characteristics are provided.

"The condensation pressure of air was determined over the range of temperature from 60 to 85 K. The experimental results were slightly higher than the calculated values based on the ideal solution law. Heat of vaporization of oxygen was determined at four temperatures ranging from about 68 to 91 K and of nitrogen similarly at four temperatures ranging from 62 to 78 K" (p. 1).

Report presenting a review of available information on the behavior of brittle and ductile materials under conditions of thermal stress and thermal shock. A number of practical methods that have been used to minimize the negative effects of thermal stress and shock are provided.

Note presenting a modified Reynolds analogy developed for the compressible turbulent boundary layer on a flat plate. When mixing-length theories are used to evaluate terms of the final expressions, it is found for air that the ratio of Stanton number to half the local skin-friction coefficient is greater than unity.