Journal article

Acoustic flows in a slightly rarefied gas

Nicholas Z Liu, Daniel R Ladiges, Jason Nassios, John E Sader

PHYSICAL REVIEW FLUIDS | AMER PHYSICAL SOC | Published : 2020

Abstract

The Boltzmann equation provides a rigorous description of gas flows at all degrees of gas rarefaction. Asymptotic analyses of this equation yield valuable insight into the physical mechanisms underlying gas flows. In this article, we report an asymptotic analysis of the Boltzmann-BGK equation for a slightly rarefied gas when the acoustic wavelength is comparable to the macroscopic characteristic length scale of the flow. This is performed using a three-way matched asymptotic expansion, which accounts for the Knudsen layer, the viscous layer, and the outer Hilbert region - these are separated by asymptotically disparate length scales. Transport equations and boundary conditions for these regi..

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University of Melbourne Researchers

Grants

Awarded by Australian Research Council Centre of Excellence in Exciton Science


Awarded by U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, Applied Mathematics Program


Funding Acknowledgements

The authors gratefully acknowledge support from the Australian Research Council Centre of Excellence in Exciton Science (Grant No. CE170100026) and the Australian Research Council Grants Scheme. D.R.L. also acknowledges support from the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, Applied Mathematics Program under Contract No. DE-AC02-05CH11231.