CFD Simulation of the FIRE II Flight Experiment

Abstract

The FIRE II flight test is simulated using the CFD code NSMB. Several models for chemical nonequilibrium, the equilibrium constant, thermal nonequilibrium and transport properties are tested and their results in convecti ve wall heat flux are compared to those by former investigators. Using the results of NSMB, a 1D radiative heat transfer analysis is performed using the ESA plasma radiation tool PARADE and the resulting radiative wall heat flux is compared to former simulations as well as to measurements during the real test flight. With a chemical nonequilibrium model by Park combined with an equilibrium constant predicted with Gibb’s Free Enthalpy and tr ansport models by Gupta, the best results in terms of convective wall heat flux and f low properties are gained. The convective wall heat flux at the stagnation point predicted by NSMB agrees very well with other investigations. Within PARADE, different accuracies in wavelength integration and different spectroscopic models are tested. With an appropriate number of discretisation points and a certain combination of spectroscopic models for atoms, the predicted radiative wall heat flux between 0.2 µm and 4 µm is a very good approximation of the measured flux during flight.