3D nozzle flow simulations including state-to-state kinetics calculation

Abstract

In supersonic and hypersonic flows, thermal and chemical non-equilibrium is one of the fundamental aspects that must be taken into account for the accurate characterization of the plasma. In this paper, we present an optimized methodology to approach plasma numerical simulation by state-to-state kinetics calculations in a fully 3D Navier-Stokes CFD solver. Numerical simulations of an expanding flow are presented aimed at comparing the behavior of state-to-state chemical kinetics models with respect to the macroscopic thermochemical non-equilibrium models that are usually used in the numerical computation of high temperature hypersonic flows. The comparison is focused both on the differences in the numerical results and on the computational effort associated with each approach.

State-Specific Study of Air in the Expansion Tunnel Nozzle and Test Section

“…However, accurately characterizing the degree of thermochemical excitation in the experimental freestream is critical for the correct interpretation of experimental data for blunt and slender body studies as well as scramjet studies, and this concept is well documented in literature [4,[14][15][16][17][18][19]. High fidelity state-to-state (StS) thermochemical nonequilibrium models do exist, though their applications have mainly focused on shock waves and converging-diverging nozzle flows where excellent work has been done [20][21][22][23][24][25][26]. Though, as mentioned earlier, converging-diverging nozzle flows are not relevant to the expansion tunnel.…”

“…Frozen Though, it is acknowledged that nozzle flows can be multi-dimensional, as shown in Ref. [24,26].…”

Problems and perspectives of state-to-state kinetics for high enthalpy plasma flows (Invited)

“…Nowadays, the StS model has been used in 2D [15] and 3D [25] calculations. It was also experimented the possibility of using General Purpose Graphical Processing Units (GP-GPU) with CUDA development environment for reactive fluid dynamics [26].…”

“…Some activities are devoted to implement the StS model in 2D/3D codes [25], also with the aid of massive parallel computing (CUDA on graphic processing units) [26]. Other researchers are proposing different macroscopic kinetic approaches [27,28,29,30] based on StS kinetics to reduce the computational load keeping the same features as the complete StS model.…”