Hypersonic Aerodynamics of Blunt Plates in Near-Continuum Regime by Improved Navier–Stokes Model

Abstract

Hypersonic argon flows over circularly blunt flat plates in near-continuum regime are numerically investigated in this study. The flows are, respectively, simulated using the direct simulation Monte Carlo (DSMC) method, the Navier–Stokes–Fourier (NSF) equations, and the DSMC data-improved Navier–Stokes (DiNS) model that is an improved continuum model with consideration of local shear nonequilibrium effects. The influences of nose radius, angle of attack, and freestream density on the local nonequilibrium characteristics and body surface aerodynamics are investigated in detail. The numerical results show that both the nose radius and the angle of attack present significant influences on the local nonequilibrium effects. Furthermore, it is found that the inaccuracy of the NSF equations for predicting aerodynamics mainly results in the error of the axial force. Compared with the NSF equations, the DiNS model exhibits remarkable improvements for predicting surface aerodynamic properties, especially the axial force, in all the simulated cases.