"The corrosion resistance of unprotected magnesium-zinc-zirconium alloy ZK60A was determined in a marine atmosphere and in tidewater. The unprotected alloy was so rapidly attacked in tidewater that it would be of no practical value in applications subject to wetting by sea water. In the marine atmosphere the rate of corrosion was much less and the alloy should give good service if adequately protected" (p. 1).

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 some preliminary calculations for airplanes of current design in order to determine the proper angles of sideslip in order to design ideal vertical tails. Existing simplified calculations for determining these values are not generally applicable to airplanes of current design, but a new solution is proposed. Results for two different airplanes are provided and suggestions for adjusting calculated sideslip values are provided.

Report presenting an analysis to give a qualitative picture of the effects of wing sweep on the upwash at the propeller airplanes of multi-engine airplanes. The method was applied to two hypothetical airplanes of the high-speed long-range type, one with an unswept wing and the other with a sweptback wing. Results regarding wing upwash, total upflow for the airplanes, upwash contribution of the airplane components, nacelles inclined, and aerodynamic exciting parameter, nacelles inclined are provided.

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.

Report presenting transient data from approximate step and sinusoidal disturbances of fuel flow on a turbojet engine operated at one constant simulated altitude and flight condition. Results regarding coefficients of differential equations, Fourier representation, frequency response, transient analysis, and a comparison of the various analytical methods are provided.

Report presenting the theoretical spanwise distributions of circulation resulting from constant angle of attack, steady rolling velocity, steady pitching velocity, and constant vertical acceleration calculated for a series of thin, sweptback, tapered wings with streamwise tips.

Revised solutions of the laminar-boundary-layer equations for cases which involved cooling at the wall combined with large pressure gradients in the main stream produced specific-weight-flow profiles which locally exceeded free-stream values. Heat-transfer and friction coefficients, boundary-layer thicknesses, and velocity, temperature, and specific-weight-flow distributions resulting from the revised solutions are presented for Euler numbers of 0.5 and 1, stream-to-wall temperature ratios of 2 and 4, and cooling-air flow rates through porous walls designated by flow parameters of 0, -0.5, and -1.

Note presenting a theoretical investigation of the effect of an increase in boundary-layer thickness on the stability of the boundary layer. The analysis also includes an investigation of the effect of an increase in boundary-layer thickness on the roughness Reynolds number and of the ability of blowing at the stagnation point to increase the boundary-layer thickness without making the boundary layer unstable.

Report presenting a theoretical study of the aerodynamic characteristics at small angle of attack of a thin, double-wedge profile in the range of supersonic flight speed in which the bow wave is detached. The calculations provide, for extremely small angles of attack, the following information as a function of the transonic similarity parameter: chordwise lift distribution, lift-curve slope, and position of center of lift.

Report presenting results of axial-load fatigue tests on notched specimens of three sheet materials: 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel. Tests were run at four levels of nominal mean stress.

Report presenting an investigation of the effects of Mach and Reynolds number on the maximum lift coefficient of a wing of NACA 64-210 airfoil section. The maximum lift coefficient was found to the a function of two independent variables, Mach number and Reynolds number, and both parameters have an important effect on the maximum lift coefficient in the ranges investigated. Results regarding observations of data and nature of Reynolds and Mach number effects are provided.

Report presenting flight tests to determine the lateral and directional stability and control characteristics of an F-47D-30 airplane. Results regarding the physical characteristics, static directional and lateral stability and control characteristics, dynamic directional stability and control characteristics, directional and lateral trim characteristics, and aileron control characteristics are provided.

From Summary: "The principles involved in the operation of several types of stall-warning devices are described and conditions under which difficulty may be experienced are pointed out. In the discussion, stall-warning devices are grouped as special stall-sensing devices and angle-of-attack-sensing devices. Methods of transmitting the warning to the pilot are also discussed. Some specific examples of stall-warning devices are illustrated and described."

Note presenting several known methods of controlling the entry and exit of hydrogen in steel as correlated with the known chemical behavior of atomic and molecular hydrogen. Some of the results of testing and a newly proposed mechanism for hydrogen control are provided.

Note presenting graphs for rapid evaluation of air-induction systems from considerations of their aerodynamic-performance parameters in combination with power-plant characteristics. The graphs cover the range of supersonic Mach numbers up to 3.0. The illustrative examples indicate that the inlet area required for optimum performance must change with altitude at a fixed Mach number as well as with Mach number at a fixed altitude.

"From a review of the different similarity approaches to compressible potential flow, the meaning and limitations of transonic similarity are traced back to their origin. Although the main text deals with the quasi two-dimensional flow, special suggestions for the case of axisymmetric bodies are added in an appendix" (p. 1).

From Summary: "A method is presented for obtaining three-dimensional unsymmetric supersonic nozzles and inlets from known axisymmetric flows. Stream-lines bounding the desired exit shape are traced through the known basic flow solution to give the required unsymmetric wall contours. Several examples are given."

Report presenting the results of an investigation of condensation phenomena in supersonic wind tunnel. Lower and upper limits for the degree of supersaturation attainable before the onset of condensation of air are discussed. A method is presented for calculating the properties of a stream containing a small fraction of condensed air.

"A derivation of the form of the incompressible turbulent skin-friction law for an insulated flat plate is made in such a way that it may be extended to compressible flows. The ratio of compressible to incompressible skin friction is obtained, and the results are shown to be in agreement with existing experimental results" (p. 1).

Report presenting a theory and method for the application of interferometry to the measurement of certain two-dimensional gaseous density fields. The theory includes the effects of optical refraction on the observed interference pattern.

Note presenting an analysis of the one-dimensional compressible flow in a rotating radial-plane impeller channel conducted in order to provide an insight into the characteristics of the passage mean flow under the influence of centrifugal forces and losses.

Note presenting an investigation carried out to study the elastic behavior after buckling of a rectangular plate reinforced with longitudinal stiffeners and subjected to compressive loads in a direction parallel to the stiffeners. Two possible buckling modes were investigated.

Report presenting an evaluation of the theoretical performance of the turbine-propeller engine with augmentation by means of compressor-inlet water injection, tail-pipe burning, and a combination of the two methods. An investigation of the effect of augmentation of variations in compressor and turbine efficiency, compressor pressure ratio, turbine-inlet temperature, and propeller-plus-gear efficiency was conducted. The investigation also include the effects of ambient humidity and temperature and degree of evaporation during compression.