Instead of solving the nonlinear differential equation which governs the compressible flow, an approximate method of solution by means of the variational method is used. The general problem of steady irrotational flow past an arbitrary body is formulated. Two examples were carried out, namely, the flow past a circular cylinder and the flow past a thin curved surface. The variational method yields results of velocity and pressure distributions which compare excellently with those found by existing methods. These results indicate that the variational method will yield good approximate solution for flow past both thick and thin bodies at both high and low Mach numbers.

Note presenting a basic theory of generalized linearized supersonic conical flow for both inside and outside the Mach cone, which was developed and applied to several specific problems including unsteady-flow conditions. A triangular lifting wing in pitching and rolling with both subsonic and supersonic leading edges was investigated and pressure coefficients were obtained.

Report presenting a linearized solution for the problem of plastic deformation of a thin plate with a circular hole in the strain-hardening range. It is based on the deformation theory of plasticity for finite strains.

Note presenting a general steady through-flow theory of nonviscous fluid in turbomachines of arbitrary hub- and casing-wall shapes with subsonic or supersonic velocity. The theory is applicable to both direct and inverse problems and is derived primarily for use in turbomachines with thin blades of high solidity with a simple approximate correction factor for blade-thickness effect.

Note presenting the equations governing the three-dimensional compressible laminar boundary layer with variable viscosity and thermal conductivity, which are shown to be simplified by the introduction of a two-component vector potential, the use of a transformation to change the equations into nearly incompressible form, and the use of a further transformation that changes the equations into nearly Cartesian form when a coordinate system appropriate to axial or conical symmetry is used. Problems involving conical potential flow are also discussed.

Report presenting a pressure-distribution investigation of a body of revolution in the 4- by 4-foot supersonic tunnel at a Mach number of 1.59. Results regarding the basic pressure-distribution data, reduction of conical-pitot-yaw-head data, four-static orifice system, flow-angle determination, other orifice systems, and general comments on theoretical prediction of pressure distribution on cone surfaces are provided.

Note presenting a method for the determination of the spanwise load distribution of a flexible swept wing at subsonic speeds. The method is based on a relaxation approach using aerodynamic loadings obtained from previously published work based on Weissinger's simplified lifting-surface theory together with simple beam theory.

Report presenting an investigation to determine the first-order vibratory stresses induced in propellers of conventional design when rotating in the flow field of a wing-nacelle-fuselage combination, which also enables an evaluation of the steps essential to the prediction of the stresses. Thrust measurements were obtained by means of propeller-wake surveys in order to define the magnitude of the force changes experienced by the blades. Results regarding the oscillating air loads and vibratory stresses are provided.

Report presenting charts to provide a convenient means for obtaining the derivatives of rotor resultant force, rotor pitching amount about the helicopter center of gravity, and rotor torque with respect to rotor angle of attack, forward speed, rotor speed, and collective pitch.

Note presenting an investigation to determine the static-thrust performance of a coaxial helicopter rotor with blades tapered both in plan form and thickness ratio in the full-scale tunnel. Tests of the coaxial-rotor and single-rotor configurations were made for a range of blade-pitch setting and for a range of tip speed up to 500 feet per second. Results regarding the hovering performance, effect of variation in directional control, and variation of rotor figure of merit with ratio of thrust coefficient are provided.

Report presenting information on the axial-load fatigue behavior of unnotched specimens of 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel. The primary objectives of the investigation were to determine fatigue strengths and measurements of damage due to stress level are provided. Results regarding static strength tests, fatigue strength tests, fatigue damage tests, and results at high and low speeds are provided.

"Liquid-water content, droplet size, and temperature data measured during 22 flights in predominately stratiform clouds through the 1948-49 and the 1949-50 winters are presented. Several icing encounters were of greater severity than those previously measured over the same geographical area, but were within the limits of similar measurements obtained over different terrain within the United States. An analysis of meteorological conditions existing during the 74 flights conducted for four winters indicated an inverse relation of liquid-water concentration to maximum horizontal extent of icing clouds" (p. 1).