化工学报 ›› 2012, Vol. 63 ›› Issue (1): 25-35.DOI: 10.3969/j.issn.0438-1157.2012.01.004

• 流体力学与传递现象 • 上一篇    下一篇

不可压热流体中气体传质扩散过程的数值模拟

雍玉梅1,杨超1,尹小龙2,林军3   

  1. 1中国科学院过程工程研究所;2美国科罗拉多矿业大学石油工程系;3南京师范大学化学与材料科学学院
  • 收稿日期:2011-05-09 修回日期:2011-07-01 出版日期:2012-01-05 发布日期:2012-01-05
  • 通讯作者: 杨超,林军

Numerical simulation of gas diffusion in an incompressible thermal fluid with lattice Boltzmann method

YONG Yumei1,YANG Chao1,YIN Xiaolong2,LIN Jun3   

  1. 1Key Laboratory of Green Process and Engineering,Institute of Process Engineering,Chinese Academy of Sciences;2Petroleum Engineering Department,Colorado School of Mines;3College of Chemistry and Materials Science,Nanjing Normal University
  • Received:2011-05-09 Revised:2011-07-01 Online:2012-01-05 Published:2012-01-05
  • Contact: YANG Chao

摘要: 控制流体流动中溶解的气体分子浓度能有效控制流动过程中的化学反应,而由热产生的自然对流能够加强气体分子的传递,因此研究气体分子在热流体流动中的扩散混合过程有重要意义。应用格子Boltzmann方法,耦合热效应和扩散效应,数值模拟了一个简化的容器中随着自然对流的发展,溶解的氧气分子在整个容器中的扩散过程。首先建立了二维9速模型的双扩散模型来模拟热量和质量的双扩散对流。为了考察不同自然对流流动对气体分子传递的影响,设计了3种不同给热条件,对不同热流动的形成过程和气体分子扩散过程进行了模拟,与文献结果吻合良好。通过详细分析热边界如何影响流动和传质过程,证实了模拟的速度场与文献数据差异的合理性,同时为控制气体传质过程提供给热条件的设计依据。

关键词: 格子Boltzmann方法, 双扩散对流模型, 传热和传质

Abstract: It is of great significance to study the mass transfer and mixing of gas in natural convection flow caused by density gradient resulted from thermal conditions because chemical reactions mainly depend on the gas molecular concentration in fluids and the natural convection can strengthen the transport of gas molecules.The diffusion process of oxygen molecules is simulated with the natural convection developed in a simplified container,coupling with the effects of thermal and mass diffusion.On the basis of impressible flow of lattice Boltzmann(LB) model D2G9,a two-dimensional nine-speed lattice Boltzmann model D2Q9 of diffusion-natural convection is first built up to simulate the diffusion processes of heat energy and mass,with non-equilibrium extrapolation boundary scheme.Then the thermal natural convection and gas mass transfer process are simulated with three kinds of thermal boundary conditions in order to analyze and explore how the thermal conditions influence the fluid flow and mass transfer of gas.The calculated results are consistent with the published data.The effect of thermal condition on the natural convection flow is analyzed and the differences in velocity distribution between the numerical data and published data are discussed.The thermal flow dependent mass transfer provides a basis for designing appropriate thermal conditions to control the chemical reaction processes.

Key words: lattice Boltzmann method, diffusion-convection model, heat and mass transfer