【摘要】 建立的Bingham流体稠密两相流动的二阶矩_颗粒动力论湍流模型(USM_theta模型)既体现了两相的作用,又体现了屈服应力所引起的附加项,并提出了USM_theta模型下考虑浓度修正值影响的两相湍流流动的算法.利用该模型对圆管内Bingham流体的单相湍流流动、稠密液固两相的湍流流动进行了计算,并和五方程湍流模型进行了比较,结果表明该模型的预测效果更好.利用USM_theta模型对含颗粒的Bingham流体的两相湍流流动进行了模拟,随着屈服应力的增加,Bing-ham流体相与颗粒相在管道中心附近的主流速度减小.液固两相湍流和Bingham流体两相湍流的计算结果表明屈服应力引起的附加项对流动有很重要的影响.更多还原

【Abstract】 The USM-theta model of Bingham fluid for dense two-phase turbulent flow is developed,which combines the unified second-order moment model for two-phase turbulence with the particle kinetic theory for the inter-particle collision.In this model,phases interaction and the extra term of Bingham fluid yield stress were taken into account.An algorithm for second-order moment model in dense two-phase flow was proposed,in which the influence of particle volume fraction was accounted for.This model was used to simulate turbulent flow of single-phase and dense two-phase in pipe,it is shown the USM-theta model has better prediction result than five-equation model,in which the particle-particle collision is modeled by the particle kinetic theory,while turbulence of both phases is simulated by the two-equation turbulence model.The USM-theta model was also used to simulate the dense two-phase turbulent flow of Bingham fluid with particles.With the increasing of the yield stress,the velocities of Bingham and particle decrease near the pipe centre,comparing the two-phase flow of Bingham-particle with that of liquid-particle,it is found the source term of yield stress has significant effect on flow.更多还原