Modeling and simulation in supersonic carbon dioxide turbulent channel flows

The present work focuses on bulk viscosity and multi-temperature effect of carbon dioxide carbon dioxide in supersonic wall-bounded turbulent flows. Mars's atmosphere consists of 95.32% carbon dioxide, for accurate predictions of surface drag and heat flux on Martian vehicles, which is necessary to take the peculiarities of carbon dioxide into account. Different with the dominant diatomic gases nitrogen and oxygen on earth, carbon dioxide is a linear and symmetric triatomic molecular. Two essential ingredients should be addressed for compressible turbulent carbon dioxide flows, the inherit large bulk viscosity (i.e., 1000 times larger than shear viscosity) and the multi-temperature effect arising from the interactions among translational, rotational, and vibrational modes. On above two concerns of carbon dioxide, current research pioneers detailed physical models and simulate supersonic wall-bounded turbulent carbon dioxide flows. Bulk viscosity and multi-temperature effect of carbon dioxide have been modeled in an extended triple-temperature BGK-type equation within the well-established kinetic framework. Numerical simulations show the bulk viscosity and multi-temperature effect of carbon dioxide enlarge the heat transfer and decrease the frictional force. Current research envisions long-term applicability for further Mars exploration.