Heat Transfer Through a Rarefied Polyatomic Gas Confined Between Parallel Plates

The conductive heat transfer through rarefied polyatomic gases confined between parallel plates maintained at different temperatures is investigated. The approach is based on the Holway kinetic model as well as on the Boltzmann equation via the DSMC scheme supplemented by the Borgnakke-Larsen collision model. The hard sphere model is applied. Results are presented for the total as well as for the translational and rotational parts of the heat flux in the whole range of the Knudsen number and for various temperature differences. The effect of the thermal accommodation coefficient is also examined. The results obtained by the Holway model and the DSMC method are in very good agreement and they compare well with experimental data available in the literature. Qualitatively the behavior of the dimensionless total macroscopic quantities is similar to that of the monatomic ones but the heat fluxes of polyatomic gases are significantly higher than the corresponding monatomic ones. It is clearly demonstrated that heat transfer simulations through rarefied polyatomic gases in MEMS cannot rely on typical monatomic modeling and on the contrary, reliable kinetic modeling for polyatomic gases must be implemented.