Report discussing an investigation to determine the effect of spin on the aerodynamic characteristics of the Army Ordnance Corps 60-millimeter T-24 mortar shell with several tail-fin configurations. Tests were performed at several airspeeds, speeds of rotation, and angles of attack. Under all test conditions, the models were statistically stable and the yawing moment increased with speed of rotation at higher angles of attack.

Report presenting an analytical method for calculating the maximum wall temperature of a tail-pipe burner or a ramjet combustion chamber cooled by air or gas flowing through a surrounding annular passage.

Memorandum presenting a discussion of the strategic-material problems of airplane engines as a whole, especially as related to parts of the engine that are not the disk or blades. Several possible approaches to the material-conservation problem are presented, including the advantages and disadvantages, and the relative gains that might result from one, or combination of a number, of these approaches.

A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compared with those computed by a more rigorous method and the procedure is applied to several airplane configurations which are believed typical of current designs. The results are generally satisfactory.

From Summary: "The combustion performance, and particularly the phenomenon of altitude operational limits, was studied by operating the annular combustor of a turbojet engine over a range of conditions of air flow, inlet pressure, inlet temperature, and fuel flow. Information was obtained on the combustion efficiencies, the effect on combustion of inlet variables, the altitude operational limits with two different fuels, the pressure losses in the combustor, the temperature and velocity profiles at the combustor outlet, the extent of afterburning, the fuel-injection characteristics, and the condition of the combustor basket."

"An analysis and calculations on the stability of the free laminar boundary layer between parallel streams were made for an incompressible fluid using the Tollmien-Schlichting theory of small disturbances. Because the boundary conditions are at infinity, two solutions of the Orr-Sommerfeld stability equations need not be considered, and the remaining two solutions are exponential in character at the infinite boundaries. The calculations show that the flow is unstable except for very low Reynolds numbers" (p. 571).

"A program to investigate the aerodynamic heat transfer of a nonisothermal hemisphere-cylinder has been conducted in the Langley 11-inch hypersonic tunnel at a Mach number of 6.8 and a Reynolds number from approximately 0.14 x 10(6) to 1.06 x 10(6) based on diameter and free-stream conditions. The experimental heat-transfer coefficients were slightly less over the whole body than those predicted by the theory of Stine and Wanlass (NACA technical note 3344) for an isothermal surface. For stations within 45 degrees of the stagnation point the heat-transfer coefficients could be correlated by a single relation between local Stanton number and local Reynolds number" (p. 1001).

An investigation was conducted to determine the effect of the inlet Mach number and entrance-boundary-layer thickness on the performance of a 23 degree 21-inch conical-diffuser - tail-pipe combination with a 2:1 area ratio. The air flows used in this investigation covered an inlet Mach number range from 0.17 to 0.89 and corresponding Reynolds numbers of 1,700,000 to 7,070,000. Results are reported for two inlet-boundary-layer thicknesses.

Report presenting an investigation in the high-speed tunnel to determine the effect of spin on the aerodynamic characteristics of a 60-millimeter T-24 mortar shell with several different tail-fin configurations. Tests were made at a range of airspeeds, speeds of rotation, and angles of attack. Results regarding forced-spin tests, free-spin tests, and zero-spin tests are provided.