Non-equilibrium gas flow and heat transfer in a bottom heated square microcavity

Abstract

The flow of a rarefied gas in a square enclosure with a bottom wall at high temperature and the other three walls at the same low temperature is investigated. The flow configuration is simulated both deterministically, using the non-linear Shakhov kinetic model and stochastically, using the DSMC method. Excellent agreement between the two approaches is obtained. The flow is characterized by the reference Knudsen number and the temperature ratio. It is found that along the side walls the velocity of the gas is not necessarily from cold-to-hot regions due to thermal creep, but from hot-to-cold as well. The effect of the flow parameters to this configuration, including the not well theoretically defined flow from hot-to-cold, is investigated and results are provided in the whole range of the Knudsen number for small, moderate and large temperature differences.