以晶格波茲曼法預測壁面上不同邊界條件對微流道內流場的影響

Influence of boundary condition in the prediction of microchannel flow with Lattice Boltzmann Method

姜文景(Wen-Ching Chiang)

指導教授 ： 林昭安

國立清華大學/工學院/動力機械工程學系/碩士(2014年)

https://doi.org/10.6843/NTHU.2014.00021

摘要

The focus of the present study is the simulations of micro-channel flow at different Knudsen numbers using lattice Boltzmann method. There are two issues to be addressed, which are the influences of the boundary implementations and wall models. In order to capture the Knudsen layer near the wall, three different wall models are
adopted here, i.e. Stop wall function(SWF), Lockerby wall
function(LWF), and Guo wall function(GWF). As for the boundary condition implementation, this is achieved by the combinations of the bounce-back rule and diffusive-scattering boundary condition. The weighting of the boundary conditions combined with different wall models is obtained by optimizations with the fully developed
channel flow results from linearized Boltzmann equations at Knudsen number ranging from 0.1 to 10. The adopted lattice models are D2Q9, D2Q13, D2Q17 and D2Q21. Among the wall models, Stop's wall model
outperforms the other two. Using the Stop wall model, all the lattice models can be optimized to produce correct linearized Boltzmann solutions. The model results also compares favorably with the DSMC results for Knudsen number from 0.1 to 10. The capability of the models to predict developing channel flow are further examined. Due to the difficulty in implementing inlet and outlet
boundary conditions for D2Q13, D2Q17 and D2Q21, only D2Q9 is
adopted. Results show that simulations with Stop wall model can produce correctly the pressure variations in response the change of the Knudsen number and reproduce the results from DSMC simulations.

關鍵字

晶格波茲曼 ； 微流道 ； 過渡流

並列摘要

無資料

並列關鍵字

LBM ； Stops' wall function ； transition ； microchannel

參考文獻

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