Starting from a mixed Boltzmann-BGK model for mixtures of monatomic gases with intra-species collisions modeled by Boltzmann operators and inter-species interactions described by relaxation terms of BGK type, we formally derive hydrodynamic equations in the regime dominated by intra-species interactions at Euler and Navier-Stokes level of accuracy. Explicit computation of transport coefficients of viscosity and thermal conductivity is also provided, showing realistic values for the Prandtl number of each species. We then discuss the shock wave structure problem for the multi-temperature Navier-Stokes description and we investigate the thickness of the shock profile for varying Mach number and different viscosity laws.
Multi-temperature hydrodynamic limits derived from a hybrid Boltzmann-BGK model
Martalo', Giorgio
2025-01-01
Abstract
Starting from a mixed Boltzmann-BGK model for mixtures of monatomic gases with intra-species collisions modeled by Boltzmann operators and inter-species interactions described by relaxation terms of BGK type, we formally derive hydrodynamic equations in the regime dominated by intra-species interactions at Euler and Navier-Stokes level of accuracy. Explicit computation of transport coefficients of viscosity and thermal conductivity is also provided, showing realistic values for the Prandtl number of each species. We then discuss the shock wave structure problem for the multi-temperature Navier-Stokes description and we investigate the thickness of the shock profile for varying Mach number and different viscosity laws.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
