Preliminary study on the influence of freestream temperature on aeroheating and correlation method

The temperature gradient at the bottom of the boundary layer is a significant factor causing aeroheating, and both the near-wall recovery temperature and wall temperature directly influence the temperature distribution at the bottom of the boundary layer. To enhance the extrapolation accuracy of aeroheating predictions from ground wind tunnel tests under low total temperature conditions to real-flight high total temperature environments, the primary influencing parameters for aeroheating in both laminar and turbulent flow regimes are derived based on dimensionless Navier−Stokes equations. Subsequently, for a standard hypersonic vehicle configuration, numerical simulations are carried out under identical Mach number and Reynolds number by separately fixing wall temperature and wall-to-freestream temperature ratio. The influence of freestream temperature on aeroheating coefficient is compared and analyzed. Finally, based on the boundary layer approximate solution theory, aeroheating correlation and conversion methods accounting for the influence of local boundary layer outer edge parameters are developed separately for laminar and turbulent flow regimes. At different temperatures, the aeroheating results computed under the calorically perfect gas assumption are respectively correlated and converted.