TY - JOUR
T1 - Switching criteria for hybrid rarefied gas flow solvers
JF - Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science
JO - PROC R SOC A
SP - 1581
LP - 1598
M3 - 10.1098/rspa.2008.0497
VL - 465
IS - 2105
AU - Lockerby, Duncan A.
AU - Reese, Jason M.
AU - Struchtrup, Henning
Y1 - 2009/05/08
UR - http://rspa.royalsocietypublishing.org/content/465/2105/1581.abstract
N2 - Switching criteria for hybrid hydrodynamic/molecular gas flow solvers are developed, and are demonstrated to be more appropriate than conventional criteria for identifying thermodynamic non-equilibrium. For switching from a molecular/kinetic solver to a hydrodynamic (continuum-fluid) solver, the criterion is based on the difference between the hydrodynamic near-equilibrium fluxes (i.e. the Navierâ€“Stokes stress and Fourier heat flux) and the actual values of stress and heat flux as computed from the molecular solver. For switching from hydrodynamics to molecular/kinetic, a similar criterion is used but the values of stress and heat flux are approximated through higher order constitutive relations; in this case, we use the R13 equations. The efficacy of our proposed switching criteria is tested within an illustrative hybrid kinetic/Navierâ€“Stokes solver. For the test cases investigated, the results from the hybrid procedure compare very well with the full kinetic solution, and are obtained at a fraction of the computational cost.
ER -