【摘要】 以Fluent软件为平台对高温多相流风洞的收缩段和水平试验段进行数值模拟。采用标准k-ε模型模拟气相流动,颗粒相为拉格朗日离散相模型。网格为非结构六面体网格且在速度及压力梯度变化较大的区域加密。模拟结果表明:收缩段壁面按照维氏曲线设计,气流稳定加速,壁面附近气流没有出现分离情况;收缩段出口速度均匀;试验段内沿程速度大小的均匀性降低但方向的均匀性增加。煤粉颗粒进入风洞试验段后,沿程两相速度差异逐渐减小,颗粒运动速度趋于稳定。模拟计算结果可供高温两相流风洞设计参考。更多还原

【Abstract】 On computational fluid dynamic(CFD)platform,Numerical simulation has been performed to study multiphase flow in high temperature wind tunnel convergent and experimental sections.The stand k-ε turbulent model with wall function is adopted and a discrete second phase is simulated in Lagrangian frame of reference.Unstructured hexahedral grids are generated for use and more nodes are located in zones with large velocity and pressure grads.The results show that gas velocity increases steadily if convergent section wall cure is designed according to Witozinsky curve and separation does not appear near wall.Outlet velocity is uniform.Along experimental sections centerline,velocity magnitude uniformity increases but drift angles decrease.Coal particles are carried by gas and accelerated.The multiphase velocity derivation gradually decreases and particles movements reach steady state in longitudinal distance of six meters.Simulation results can be used for wind tunnel design.更多还原