Computational and experimental investigation of near-field sonic boom of a HTV-2 type hypersonic boost gliding vehicle

Understanding and prediction of sonic boom are critical for the development of the next generation hypersonic vehicles. Low-boom design not only can minimize the thunderclap-like acoustic noise, but can enable higher propulsion efficiency as well. Before this project, hypersonic sonic boom measurements for slender bodies are not available in the literature. In this study, a Hypersonic Technology Vehicle 2 (HTV-2) type boost gliding vehicle (BGV) model, with high lift-to-drag ratio L/D= 2.4 − 3 (varying with the pitch angle), was designed and fabricated. An off-body pressure measurement device was fabricated for the desired sonic boom (i.e., over-pressure) signature measurement. The first set of hypersonic sonic boom shock tunnel tests was then conducted using the newly fabricated platform. The tests were run with different Mach numbers and pitch angles. Computational fluid dynamic (CFD) simulations were well validated by the shock tunnel test data. Using both fully laminar and fully turbulent (using the Spalart-Allmaras (SA) Reynolds-averaged Navier–Stokes (RANS) model) CFD simulations, potential laminar-to-turbulent transition locations were identified based on the agreement between the laminar or turbulent simulation and the surface sensor measurement of both heat transfer and pressure. CFD simulation indicated that the potential transition has very limited impact on the peak over-pressure, but has significant impact on the tail of the signature. CFD prediction falls within the uncertainty ranges of the off-body pressure measurement data, but the measurement uncertainty needs to be improved in future shock tunnel tests.