改进的随机轨道模型

在随机轨道模型中，由于气相脉动速度对分散相颗粒作用的间歇性，使得井非在控制体内轨道上的每一点都可以代表该轨道参与颗粒相平均特性的统计计算，从而出现随机轨道模型往往低估颗粒相湍流脉动的情况．为此，本文提出了一种改进的随机轨道模型，在该模型中，分散相的时平均量在由其自身湍流脉动所确定的随机轨道上输运．与常用的随机轨道模型相比，其具有计算量小、计算结果合理且易于得到和分散相入口湍流脉动状况易于考虑等特点．对一简单已知流场的预报结果合理正确，克服了常用的随机轨道模型低估颗粒相湍流脉动的困难．

AN IMPROVED STOCHASTIC SEPARATED FLOW MODEL

When the conventional stochastic separated flow (SSF) model is used, not all the points on the trajectory can be selected for statistical calculation to predicate turbulent two-phase flow due to the intermittent action of gas-phase turbulence, so the prediction results of the dispersed phase are always underestimated. In order to overcome these difficulties, an improved stochastic separated flow (ISSF) model is proposed. In this model, the mean properties of dispersed phase including velocity and turbulent kinetic energy are transported along its stochastic trajectory. Comparing with the SSF model, the results using the ISSF model are more reasonable and easier to be obtained for a test case, and also the dispersedphase turbulence at the beginning of the stochastic trajectory are easier to be considered.