液滴撞击液膜喷溅过程的LBM模拟

Simulation of Drop Impact on Liquid Film Using LBM

气液两相流动现象广泛存在于自然界和工程应用中,而液滴撞击液膜后产生喷溅的过程则是这一类问题的典型代表.采用格子Boltzmann方法(LBM)对上述过程进行了数值模拟.采用基于"单相"(single-phase)模型的LB两相流方法计算得到了3组Reynolds数(Re)和Weber数(We)组合下液滴撞击液膜后所产生的3种效应.结果表明,随着We数和Re数的不断增大,液滴撞击液膜后将产生铺展、喷溅以及喷溅并伴有小液滴脱落等不同现象,计算所得的结果与实验及理论分析的结果相吻合,表明了LBM研究气液两相流动问题的可行性.

Impinging of a liquid drop onto a thin film of the same liquid is a classic problem of gas-liquid two phase flows which widely exists in the nature as well as in many industrial applications. In this paper, the impinging process is simulated numerically with the lattice Boltzmann method （LBM）. This is a novel method in computational fluid dynamics and has many advantages due to its meso-scale foundation compared to macro-scale equation based traditional methods. A so-called ＂single-phase＂ lattice Boltzmann model for interface fluid flow is used to obtain the three important characteristics of impinging with three different combinations of Reynolds number （Re） and Weber number （We）. Numerical results show that different phenomena of deposit, splash, and splash with separated fluid drops erupted during impinging will take place as Re and We increase. Numerical results are in good agreement with experimental and analytical results, showing usefulness of LBM in studying gas-liquid two phase flows.