方形旋风分离器内气固两相流湍流特性的研究

应用三维颗粒动态分析仪（3D－PDA）对方形下排气旋风分离器内气固两相流场进行了实验研究，并对流场、脉动速度、颗粒浓度、湍动能、湍流强度等的分布做了讨论。方形旋风分离器的流动具有Rankine涡 的特点，即中心部分为强制涡区，边壁附近是准自由涡区。边角处因颗粒与壁面间的相互碰撞引起的准层流运动，并使得颗粒湍流脉动强烈，湍流动能和局部湍流强度在边角附近取得较大值，表明此时两相流耗了气流的能量较多，是造成分离器压力损失的主要区域之一。边角有利于颗粒分离。研究结果为结构优化提供了基础数据，并为今后的数值模拟研究提供了实验对比。

Experimental Study of the Turbulent Flow Characteristics of Gas-solid Dual-phase Flows in a Square-shaped Cyclone Separator

A three dimensional particle dynamics analyzer was employed to study the gas solid dual flow field in a square shaped cyclone separator along with a discussion of the distribution of the flow field, pulsation velocity, particle concentration, turbulent kinetic energy and turbulent flow intensity, etc. The flow in the square shaped cyclone separator has the features of a Rankine vortex, i.e., a forced swirling vortex zone at the central portion and a quasi free vortex zone near a lateral wall. The quasi laminar flow movement at the corners due to particle/wall face mutual collision gives rise to an intense particle turbulent flow pulsation. The turbulent flow kinetic energy and local turbulent flow intensity attain a relatively great magnitude near the corners. This indicates that the dual phase flow has consumed a comparatively large amount of gas flow energy near the corners. The latter are the chief zones, where the pressure loss of the separator takes place. These corners were also found to be beneficial to particle separation, mainly because the intense pulsation consumes the kinetic energy of the particle and gas flow vortex movement. The study results can provide basic data for the structural optimization and also experimental contrast information for performing further numerical simulation research.