Aero-heating in hypersonic continuum and rarefied gas flows

The prediction of aero-heating in hypersonic continuum and rarefied gas flows is challenging work in fluid dynamics. This study introduces Eu-type generalized hydrodynamic equations (Eu Equations) to predict hypersonic aero-heating in the continuum and rarefied regions. An attempt has been made to analyze aero-heating at Kn numbers from 0.01 to 0.5 by using the present model, Navier-Stokes-Fourier (NSF) and Direct Simulation of Monte Carlo (DSMC). The results show that NSF over estimates the peak aero-heating from 17% for Kn = 0.04 to almost 46% for Kn = 0.5 compared with that of DSMC. The aero-heating predicted by the Eu Equations has good agreement with that of DSMC but tends to be lower than that of NSF. An analysis was given by the constitutive relations to explain the over-estimation of NSF on hypersonic aero-heating. This study can be regarded as the first attempt to implement Eu Equations for the investigation of hypersonic aero-heating and explains the difference between the results of NSF and DSMC in the simulations of continuum-rarefied gas flows. (C) 2018 Elsevier Masson SAS. All rights reserved.