Investigation of Differences Between Measured and Predicted Pressures in AEDC/VKFHypersonic Tunnel B

摘要

A study has been carried out to assess the effect of flow nonuniformities in AEDCTunnel B on surface pressures of slender bodies. The approach taken was to use flow profiles measured in a recent calibration program as inflow boundary conditions for a CFD solution to compare with the idealized case where a uniform free stream is assumed. The results of this study indicate that flow nonuniformities are at least partially responsible for discrepancies observed at low Reynolds number (Re/L = 1,000,000/ft) on slender axisymmetric bodies at zero angle of attack. There is no corresponding effect at high tunnel Reynolds number (Re/L = 3,500,000/ft). At high Reynolds number, for angles of attack that displace the nose of the vehicle more that 6-7 in. from the tunnel centerline, there is a small increase in surface pressure caused by a radial variation in Mach number.