壁面约束下椭球颗粒曳力特性研究OA北大核心CSTPCD

Fluid-particle two-phase flows are widely encountered in nature and engineering applications,and particles in these flows are usually non-spherical and constrained by the nearby wall.Numerical simulation based on the Euler-Lagrange method has become an important approach for the design of two-phase flow systems with non-spherical particles,but its accuracy is limited by the non-spherical particle drag model.In this study,the direct numerical simulation(DNS)is performed to investigate the drag characteristics of an ellipsoidal particle at a finite Reynolds number(0.5≤Re≤10)for different attack angles between the particle orientation and the incoming flow,as well as different particle-wall gaps.The variation of drag coefficients under different conditions is analyzed and compared,and the influence of the Reynolds number,attack angle and wall gap on the drag coefficient of an ellipsoidal particle is explored.The applicability of existing models for predicting the drag force of an ellipsoidal particle in the freestream is evaluated,and finally a prediction model for the drag force of an ellipsoidal particle with the near-wall correction is developed,which can provide significant improvement for the numerical simulation of non-spherical particle-laden flows.