Unified Flow Solver Combining Boltzmann and Continuum Models for Simulations of Gas Flows for the Entire Range of Knudsen Numbers

We have developed a Unified Flow Solver (UFS) for simulations of gas flows for the entire range of Knudsen numbers from rarefied to continuum regimes JSAR, AristovAIAA2006. The UFS methodology is based on the direct numerical solution of the Boltzmann equation for rarefied flow domains bookAristov, cherem98 and the kinetic schemes of gas dynamics for the continuum flow domains Xu2001, Ohwada2006. This approach enables an easy coupling of kinetic and continuum solvers because similar numerical techniques are used for solving both the Boltzmann and continuum equations. The UFS can separate rarefied and continuum domains and use appropriate solvers to combine efficiency of continuum models with accuracy of kinetic models.