DEVELOPMENT OF FLOW AND HEAT TRANSFER MODELS IN HYPERSONIC RAREFIED GAS DYNAMICS

Abstract

The Quantum Kinetic model used to predict the shock wave structure and the heat flux at the surface of the vehicle. The dsmcFoam solver is modified to include the Quantum Kinetic chemical reaction model for the hypersonic Martian re-entry. An open-source chemistry model based on Quantum-Kinetics (QK) is presented for the Direct Simulation Monte Carlo method. Chemistry modeling for the Martian atmosphere under rarefied reentry conditions are analyzed in this study. An eight-species (CO2, N2, CO, O2, NO, C, N, and O) chemistry model is used to simulate the chemical reactions in the Martian environment. The QK model is based on the vibrational relaxation process of the molecule. A vibrational relaxation procedure for more than one vibrational modes is implemented to simulate various reactions in polyatomic molecules such as CO2. The reaction rates are validated with previous data based on the total collision energy model of Boyd, Arrhenius rates as well as with the experimental data. The reaction rates obtained in this work are found to be in very good agreement with previous results for near-equilibrium and non-equilibrium conditions. In this work, hypersonic reacting flow over the Crew Exploration Vehicle (CEV) is simulated using the Direct Simulation Monte Carlo method under the rarefied gas conditions. To account for hightemperature, non-thermodynamic equilibrium effects, the dsmcFoam solver is modified to include vibrational relaxation and chemical reactions. The chemical reactions are modeled using the Quantum Kinetics approach. This paper simulates the axisymmetric flow around the spacecraft in the Martian atmosphere. The chief constituent of the Martian atmosphere is CO2, which has four vibrational modes. We extend the relaxation and dissociation processes in the DSMC code to include all these modes. The chemical exchange reactions are considered only in the stretching mode of vibration. Our results show good agreement for the Earth’s atmosphere with other published results for the Martian atmosphere.