EFFECT OF CHEMICAL NON-EQUILIBRIUM ON FLOW PARAMETERS IN THE INTERMEDIATE HYPERSONIC REGIME
The new solver hypersonicIithFoam has been developed in the OpenFOAM framework. OpenFOAM has rhoCentralFoam which is a density based N-S solver, is used as a base solver. Additional features are incorporated to model reacting flows, variable multi-species diffusion and thermodynamic properties of high-temperature air. The solver is implemented to model the transport properties based on a kinetic theory for its
widespread applicability. Viscosity and Thermal conductivity are obtained using the model based on Lennard-Jones potential, and Chapman-Enskog diffusivity model is used to compute binary diffusion coefficient. Multicomponent mixture properties are calculated based on a mole fraction. All species are assumed to be in thermodynamic equilibrium, so the state of the gas is governed by single equilibrium temperature. The solver is tested with the available experimental data for Heat flux and coefficient of pressure Cp distribution over a surface of ELECTRE article. The hypersonic solver is shown significant improvement over a conventional compressible solver. Simulations are carried out for the flow over a sphere at different altitudes using both the conventional and the hypersonic solver for qualitative and quantitative comparisons. Post shock temperature and peak heat flux values are remarkably reduces due to the implementation of real gas effects and air chemistry. Rarefaction effects become significant from 70 km.