Numerical Study on Two-Dimensional Micro-Channel Flows Using the Gas-Kinetic Unified Algorithm

Numerical Study on Two-Dimensional Micro-Channel Flows Using the Gas-Kinetic Unified Algorithm

Year:    2018

Communications in Computational Physics, Vol. 23 (2018), Iss. 5 : pp. 1393–1414

Abstract

Based on the Boltzmann model equation, the Gas-Kinetic Unified Algorithm (GKUA) will be developed to simulate the two-dimensional micro-scale gas flows with irregular configuration. The numerical scheme for the direct evaluation of the unified velocity distribution function in the computable model of the Boltzmann equation and the multi-block grid docking technology are constructed, and the numerical procedures of characteristic-based boundary conditions are presented to model the gas-surface interaction and the inlet/outlet boundaries for the two-dimensional micro-channel flows. The two-dimensional Couette flow, the pressure-driven micro-channel flows, and the irregular micro-orifice flows in different scales are numerically solved from high rarefied free-molecule to near-continuum flow with the Knudsen numbers of $Kn$ = 100−0.01. The computed results are compared and validated with the DSMC data in the transitional flow regime and the slip N-S solutions in the near-continuum flow regime, in which the GKUA is verified accurately and smoothly to simulate the two-dimensional micro-channel flows with strong adaptability and good precision. The micro-channel flow features with the wide range of $Kn$ numbers in the near-continuum slip and transitional flow regimes are revealed, and it is probable to provide a way in developing a new numerical algorithm for micro-scale flows.

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Journal Article Details

Publisher Name:    Global Science Press

Language:    English

DOI:    https://doi.org/10.4208/cicp.OA-2016-0232

Communications in Computational Physics, Vol. 23 (2018), Iss. 5 : pp. 1393–1414

Published online:    2018-01

AMS Subject Headings:    Global Science Press

Copyright:    COPYRIGHT: © Global Science Press

Pages:    22

Keywords:    Micro-channel flow Boltzmann model equation gas molecular velocity distribution function gas-kinetic unified algorithm non-equilibrium rarefied effect of micro-scale flow.