基于MP-PIC方法对提升管内气固流动的数值模拟

Numerical Simulation of Gas-solid Flow in Riser based on MP-PIC Method

针对提升管气固两相流动中的颗粒运动规律,基于Open FOAM开源软件,通过多项质点网格法(MP-PIC)模拟了三维提升管内的气固流动特性,其中颗粒间的碰撞过程采用Harris&Crighton固相应力模型,气固间的作用力采用Gidaspow曳力模型。结果表明:模拟结果准确地呈现出颗粒和气体在提升管内边壁浓、中间稀的环-核流动结构。时均颗粒浓度沿径向呈现中间稀、边壁浓的分布结构,在径向相对位置(r/R)处于-0.5~0.5时,颗粒浓度的模拟数值大多小于0.02;而时均颗粒速度分布恰恰相反,并且在径向相对位置(r/R)处于±(0.5~1)时,颗粒速度大多小于1 m/s。时均颗粒浓度在轴向相对位置0.1m以上时下降缓慢,而时均颗粒轴向速度在提升管相对高度大致为0.5m以上时变化趋于稳定。

In view of the particle motion law in the gas-solid two-phase flow of the riser, based on the Open FOAM open source software, the multi-phase particle-in-cell(MP-PIC) method is used. The collision process between particles is modeled by Harris & Crighton solid stress model, drag between gas and particles was calculated by Gidaspow model.The results show that the simulation results accurately present a ring-core flow structure with dense particles and gas in the sidewall and thin in the middle of the riser. The time-average particle concentration presents a distribution structure of thin in the middle and thick in the sidewall along the radial direction. When the radial relative position(r/R) is-0.5~0.5,the simulation values of particle concentration are mostly less than 0.02. The time-averaged particle velocity distribution is the opposite, and when the radial relative position(r/R) is ±(0.5~1), the particle velocity is mostly less than 1m/s. The time-average particle concentration decreases slowly when the axial relative position is more than 0.1m, while the time-average particle axial velocity tends to be stable when the relative height of the riser is more than 0.5 m.