中文摘要：

生物过滤技术因其具有有效性、低成本和环境友好等优点引起了人们的广泛关注。该技术主要通过生物过滤器去除含有H2 S等废气的有毒有害气体。运用格子Boltzmann方法对三种生物过滤器模型中多孔介质的非均匀性流动进行了数值模拟。数值模拟结果表明，多孔介质的性质和进口流动条件对临界Rayleigh数有显著影响，临界Rayleigh数随着多孔介质的孔隙度和Darcy数的增大而逐渐变小，并随着进口Reynolds数的增大而逐渐变大。所得结果可望为生物过滤器的优化设计提供一个合理的理论依据。

英文摘要：

Biofiltration technology has received much attention because of its effectiveness, economy and environmentally friendly property, which can filter the odors caused chiefly by H2S via the biological treatments. In this study, the lattice Boltzmann method is adopted to numerically investigate the heterogeneous flow in three porous biofilter models. The numerical results indicate that the property of porous media and the inlet flow condition have significant influence on the value of critical Rayleigh number. With the increase of Darcy number and porosity, the critical Rayleigh number will gradually decrease;however, it will steadily increase with the augment of inlet Reynolds number. The present study is helpful to provide a rational theoretical guidance for the optimized design of biofilters.