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Persistent URL http://purl.org/net/epubs/work/35509
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Record Id 35509
Title A thermal lattice Boltzmann model for low speed rarefied gas flow
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Abstract With development of micro/nano-devices, low speed rarefied gas flows have attracted significant research interest where successful numerical methods for traditional high speed flows including the direct simulation of Monte Carlo method become computationally too expensive. Since the Knudsen number is usually up to the order of unity in a micro/nano flow, one approach is to use continuum methods including the Navier-Stokes-Fourier, Burnett/super Burnett equations, and 13 momments models. Limited success has been achieved because of theoretical difficulties and/or numerical problems. Recent developed lattice Boltzmann equation (LBE) could be another fundmentally different approach close to the kinetic methods but with significantly smaller computational cost. However, despite lattice Boltzmann method is an appealing method for rarefied gas flows at micro/nano scales, there are some hurddles need to be overcome, e.g. capturing velocity slip and temperature jump, predicting stresses and heat flux acurately. The success of recent attempts of applying LBE model for rarefied gas motion has been mainly focused on isothermal flows. In this paper, thermal rarefied gas flows will be tackled. Because of unique feature of micro/nano flows, a simplified thermal lattice Boltzmann model with two distribution functions can be used. In addition, the kinetic theory boundary condition for the number density distribution function can be extended to construct thermal boundary condition. The model has been validated in the slip flow regime against the solutions of the Navier-Stokes- Fourier equations for shear and pressure driven flows between two planar plates. Moreover, the present thermal LBE model can capture some unique flow characteristics that the Navier-Stokes-Fourier equations fail to predict. The present work indicates that the thermal lattice Boltzmann model is a computationally economic method that is particularly suitable to simulate low speed thermal rarefied gas flows.
Organisation CCLRC , CSE , CSE-CEG
Keywords Physics
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Language English (EN)
Type Details URI(s) Local file(s) Year
Report DL Technical Reports DL-TR-2006-002. 2006. DL-TR-2006-002.pdf 2006