Equilibrium Calculation of Augmented Shock-Tunnel Heat Flux at High-Pressure and High-Enthalpy Conditions

摘要

RECENTLY, shock-tunnel experiments have been conducted at high-pressure and high-enthalpy conditions such as a reservoir pressure (P_0) of 50 MPa and a reservoir enthalpy (H_0) of 20 MJ/kg in order to study laminar-to-turbulence transition on hypersonic vehicles [1-3]. In those experiments, unexpected large wall heat flux to test models was measured, which was not observed at low-pressure conditions. The cause of the heating augmentation remains an open issue.To investigate the heating augmentation, viscous shock layer calculation for wall heat flux in thermal-chemical equilibrium has been performed in this work. This calculation was expected to produce reasonable results for the present condition because 1) an assumption of thermal-chemical equilibrium is mostly adequate for high-pressure flows and 2) wall heat flux in a shock tunnel is insensitive to the thermal-chemical state of the nozzle flow [4,5]. This Note discusses the heating augmentation at high-pressure and high-enthalpy conditions, comparing calculations in this work with measured data.