介观尺度流体绕流球体的耗散粒子动力学模拟

摘要

Dissipative particle dynamics（DPD） is used to investigate the flow passing through a three-dimensional sphere within two parallel plates.The sphere and the plates are composed of frozen DPD particles which are in an equilibrium state.The fluid is driven by a dimensionless external force exerting on each fluid particle.The force on the sphere is computed from the total particles consistituting the sphere.After the flow is fully developed,the obtained results,including the force exerted on the sphere is computed,and then we can calculate the drag coefficient.The accuracy and the reliability are compared with classical results.The results show that the DPD method can predict drag coefficient accurately when Re is less than 100.However,when Re is bigger than 100,the results deviate from analytical values,which is due mainly to the fluid compressibility.%采用耗散粒子动力学（dissipative particle dynamics,DPD）方法,对两平行平板间流体绕流三维球体进行了计算.球体和平行平板由达到平衡状态的冻结DPD粒子组成,流体在不同无量纲外力驱动下流动,球体受力由组成球体的所有冻结DPD粒子求和得到.流动达到充分发展后,输出球体在流动方向的受力,并计算球体的阻力系数,与文献中的关联式进行了对比.结果表明,在Re≤100的范围内,DPD方法能较准确地计算出阻力系数,在较大雷诺数时,由于流体的压缩性导致计算结果出现差异.