Parametrized numerical analysis of hypersonic flow field

Since the end of World War II the interest in high-velocity aerodynamic technologies has grown significantly and research in hypersonic flows has become a strategic field of study. These developments have led to the engineering of heat shields used atmospheric entry modules, providing thermal protection to the crew and space probes, but also to the design of scramjet propulsion system. Clearly the military industry has got a substantial support in the production of long range and high speed weapons, such as hypersonic cruise missiles. Experimental analysis remains a fundamental pillar in design and test processes of hypersonic technologies, however this approach requires appropriate testing facilities which have significant operational costs. Several numerical methods have been developed in the lasts decades in order to properly simulate high-supersonic and reacting flows, providing a reliable tool suitable to investigate hypersonic regime. In this work has been analysed the flow field around a cone-like axisymmetric shape, using the Siemens' commercial Computational Fluid Dynamics (CFD) code, STAR-CCM+. Firstly, a comprehensive theoretical background has been widely described whit a focus on high temperature effects, which characterize hypersonic flow regime. Then, an essential code has been written in order to proper calculate air equilibrium condition at different temperatures and pressures. It allows to freely choose which chemical species must be included in the calculations; nevertheless its use has been limited to examine Earth's multispecies atmospheric models. This procedure allowed to identify the thermodynamic conditions, at equilibrium, under which the gas dissociation and ionization occur. Lastly, a proper parametric numerical study of the hypersonic flow field around a cone-like body has been completed. The physical model adopted in these simulations included a seven species air model. The computational domain also include a large portion of cone's wake in order to highlight how plasma evolves as it is transported downstream. The parameters chosen for this analysis were the free stream air properties established by the standard Earth's atmosphere model and the free stream Mach number. A steady state numerical simulation has been carried out for each pair of altitude-Mach number, ensuring an appropriate convergence of the solution.