Performance characteristics of underslung vertical wedge inlet with porous suction at Mach numbers of 0.63 and 1.5 to 2.0.

Report presenting testing of the performance of a ventrally mounted inlet having a variable-angle vertical-wedge compression surface determined at several Mach numbers for angles of attack, angles of yaw, and wedge angle. A solid wedge and wedges with two different porosities were tested. Results regarding the inlet flow-field survey, comparison of inlet configurations, performance of the inlet, effect of free-stream Mach number at angle of attack of 2 degrees, effect of angles of attack and yaw, diffuser total-pressure distortion, fuselage boundary-layer-removal scoop, and effective thrust comparison are provided.

"Recent results of the effects of Mach number, stream turbulence, leading-edge geometry, leading-edge sweep, surface temperature, surface finish, pressure gradient, and angle of attack on boundary-layer transition are summarized. Factors that delay transition are nose blunting, surface cooling, and favorable pressure gradient. Leading-edge sweep and excessive surface roughness tend to promote early transition. The effects of leading-edge blunting on two-dimensional surfaces and surface cooling can be predicted adequately by existing theories, at least in the moderate Mach number range" (p. 1).

The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude of 70,000 feet. A compressor-bleed-air weight flow of 2.7 pounds per second was assumed for the coolant; ram air was considered as the other fluid. Pressure drops and inlet states of both fluids were prescribed, and ranges of compressor-bleed-air temperature reductions and of the ratio of compressor-bleed to ram-air weight flows were considered.