2024/12/12 by Yufeng Wei, Junzhe Cao, Wei, Yufeng +3
Mathematics · #Gas Dynamics and Kinetic Theory
paper · pdf · doi:10.48550/arxiv.2412.09787
Reactive flows for rarefied gas mixtures involve a multi-scale transport\ncharacterized by particle collisions and free streaming, and non-equilibrium\nphysics containing multi-species interactions, and chemical non-equilibrium.\nThese flows are pivotal in aerospace engineering and semiconductor\nmanufacturing, impacting spacecraft control and thermal protection in\nnear-space flight, and plasma etching for chip processing. Therefore, the\nsimulation of these multi-scale and non-equilibrium flow is of scientific and\nindustrial significance. Following the methodology of direct modeling, the\nunified gas-kinetic scheme (UGKS) is constructed to describe the multi-scale\ntransport of gas molecules across all flow regimes. This study extends the UGKS\nto the reactive flows with chemical non-equilibrium for the capture of more\ncomplex flow physics. Test cases, including shock structures, hypersonic flows\naround a two-dimensional cylinder and the three-dimensional re-entry and space\nvehicle, and nozzle plume flow into a vacuum, are used to validate the UGKS\nthrough the comparison with the direct simulation Monte Carlo method. The study\nshows that the methodology of direct modeling and the extended UGKS have great\npotential for simulating multi-scale flows with complex non-equilibrium\nphysics.\n