CFD code calibration and inlet-fairing effects on a 3D hypersonic powered-simulation model

Abstract

A three-dimensional (3D) computational study has been performed addressing issues related to the wind tunnel testing of a hypersonic powered-simulation model. The study consisted of three objectives. The first objective was to calibrate a state-of-the-art computational fluid dynamics (CFD) code in its ability to predict hypersonic powered-simulation flows by comparing CFD solutions with experimental surface pressure data. Aftbody lower surface pressures were well predicted, but lower surface wing pressures were less accurately predicted. The second objective was to determine the 3D effects on the aftbody created by fairing over the inlet; this was accomplished by comparing the CFD solutions of two closed-inlet powered configurations with a flowing-inlet powered configuration. Although results at four freestream Mach numbers indicate that the exhaust plume tends to isolate the aftbody surface from most forebody flowfield differences, a smooth inlet fairing provides the least aftbody force and moment variation compared to a flowing inlet. The final objective was to predict and understand the 3D characteristics of exhaust plume development at selected points on a representative flight path. Results showed a dramatic effect of plume expansion onto the wings as the freestream Mach number and corresponding nozzle pressure ratio are increased. NomenclatureM Mach number NPR nozzle pressure ratio, p t,jet / p pressure, Pa Re Reynolds number, 1/m T temperature, K X aftbody aftbody length from cowl trailing edge to body trailing edge x, y, z streamwise, spanwise, and vertical coordinates Y aftbody model fuselage maximum semispan α angle of attack, degrees ρ density, kg/m 3 Subscripts freestream conditions throat conditions at the internal nozzle throat t, jet jet total conditions wall conditions at a solid wall boundary p ∞ ∞

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