Influence of intermolecular potentials on rarefied gas flows: fast spectral solutions of the Boltzmann equation

Lei Wu, Haihu Liu, Yonghao Zhang, Jason M. Reese

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The Boltzmann equation with an arbitrary intermolecular potential is solved by the fast spectral method. As examples, noble gases described by the Lennard-Jones potential are considered. The accuracy of the method is assessed by comparing both transport coefficients with variational solutions and mass/heat flow rates in Poiseuille/thermal transpiration flows with results from the discrete velocity method. The fast spectral method is then applied to Fourier and Couette flows between two parallel plates, and the influence of the intermolecular potential on various flow properties is investigated. It is found that for gas flows with the same rarefaction parameter, differences in the heat flux in Fourier flow and the shear stress in Couette flow are small. However, differences in other quantities such as density, temperature, and velocity can be very large.

Original languageEnglish
Article number082002
Number of pages14
JournalPhysics of Fluids
Issue number8
Publication statusPublished - 25 Aug 2015



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