壁面约束下椭球颗粒曳力特性研究  

Study on drag characteristics of an ellipsoidal particle under wall constraint

作　　者：鲁贤民 杨渐志 顾海林 吴灵波 LU Xianmin;YANG Jianzhi;GU Hailin;WU Lingbo(College of Civil Engieering,Hefei University of Technology,Hefei 230009,China;College of Metrology and Measurement Engineering,China Jiliang University,Hangzhou 310018,China)

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]中国计量大学计量测试工程学院,杭州310018

出　　处：《空气动力学学报》2024年第3期19-29,共11页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(12302331)。

摘　　要：颗粒两相流系统广泛存在于自然界和工程应用中,实际颗粒往往并非球形且受其附近壁面的影响。基于欧拉-拉格朗日方法的颗粒两相流数值模拟已成为非球形颗粒两相流系统设计的重要工具,然而其准确性受限于非球形颗粒曳力模型。因此,深入研究壁面约束下非球形颗粒曳力特性并发展近壁修正预测模型具有重要意义。本文采用直接数值模拟方法对有限雷诺数(0.5≤Re≤10)下,不同颗粒长轴取向与来流之间的夹角以及颗粒-壁面间距的单椭球颗粒曳力特性开展详细数值研究,分析比较不同工况下曳力系数的变化,探明雷诺数、攻角以及壁面间距对椭球颗粒曳力系数的影响规律,并评估现有自由流中椭球颗粒曳力关系式的适用性,最后发展了考虑近壁修正的椭球颗粒曳力预测模型,为优化非球形颗粒两相流数值模拟工具提供重要支撑。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.

关 键 词：颗粒两相流 椭球颗粒 曳力系数 壁面效应 雷诺数 直接数值模拟 

分 类 号：O354[理学—流体力学]