"It has been known for some time that the velocity of sound is not the upper limit for potential flow. S. A. Chaplygin in his paper "On Gas Jets" (NACA TM No. 1063) carried out some interesting proofs on the existence of solutions and gave proofs relating to maxima and minima of certain functions. In the present paper these proofs are extended to include the supersonic potential air-flow field adjacent to the subsonic region treated by Chaplygin" (p. 1).

"Initial shocks of the type that occur on airfoils at stream Mach numbers less than unity are shown to satisfy a certain condition, namely, that the local Mach number behind the shock wave tends to approach unity. This result is, in nature, similar to the classic condition of Kutta on the circulation" (p. 1).

Report presenting flow coefficients of an intake valve, seat, and port combination were measured under steady- and intermittent-flow conditions. Tests were conducted at large and small pressure drops over an engine-speed range of 800 to 3600 rpm.

Report presenting an investigation of the effects of Mach and Reynolds numbers on the maximum lift coefficient of aircraft. Flight testing was conducted on six airplanes outfitted with measuring tools and flow at various Mach and Reynolds numbers.

Note presenting a multiple-bridge circuit that eliminates contact-resistance errors of the first order between the arms of the ordinary Wheatstone bridge. The circuit is applied to the elimination of the effects of contact-resistance variations that may occur in resistance strain-gage measurements made through switch contacts or slip rings. The general theory is derived and correct circuits and constructions are described.

Report presenting an analysis which indicates that for aerodynamic efficiency, wings designed for flight at supersonic speeds should be swept back at an angle greater than Mach angle and the angle of sweepback should be such that the component of velocity normal to the leading edge is less than the critical speed of the airfoil sections. This principle can also be applied to wings designed for subsonic speeds.

From Introduction: "An analysis of a square web above the buckling load was presented in reference 1. The analysis of reference 1 therefore was repeated for a shear web with depth/width = 2.5. Comparison of the results with those for the square web then would indicate the effect in the depth-width ratio."

"Principles of similarity and other factors in the design of models for photoelastic testing are discussed. Some approximate theoretical equations, useful in the analysis of results obtained from photoelastic tests are derived. Examples of the use of photoelastic techniques and the analysis of results as applied to uniform and tapered beam columns, circular rings, and statically indeterminate frames, are given. It is concluded that this method is an effective tool for the analysis of structures in which column action is present, particularly in tapered beam columns, and in statically indeterminate structures in which the distribution of loads in the structures is influenced by bending moments due to axial loads in one or more members" (p. 1).