三维槽道两相流颗粒运动的大涡模拟

LARGE EDDY SIMULATION OF PARTICLE IN DE GAS-PARTICLE TURBULENT HORIZONTAL CHANNEL FLOW

利用基于动态粘性亚网格模型的大涡模拟方法,分别模拟了Reτ=180的三维槽道湍流内的三种颗粒,以及Reτ分别为180和395时的塑料颗粒的运动状况。其中气相控制方程的求解采用分步投影方法,泊松方程采用基于FFT的快速求解,颗粒的拉氏控制方程采用二阶龙格-库塔积分．模拟统计得到了流体和颗粒的平均速度、脉动速度等,不同的颗粒在流场中(特别是近壁区)表现出来了不同的行为,并再现了颗粒在壁面附近局部富集的现象．随Reτ提高,颗粒各方向上的速度脉动都有所增强．

Particle transport in fully-developed turbulent channel flow has been investigated by large eddy simulation（LES） of the incompressible Navier-Stokes equations, where the subgrid-scale is modeled using dynamic eddy viscosity model. The governing equation of gas species were solved with finite difference method, and the Possion equation by direct FFT method. The pressure-velocity coupling were implemented with a fraction-step projection method. And the particle equation is solved with two-order Runge-Kutta scheme. In this paper, Three kinds of suspended particles were investigated at ReT=180 （based on friction velocity and channel half width） and plastic particles was investigated at ReT=180 and ReT=395. It shows that different behaviors in the flow field, especially near the wall. And the numerical results show that the particles tend to concentrate in the regains near the wall.