圆管突扩气固两相流动湍流变动研究  

STUDY ON TURBULENCE MODULATION OF GAS-SOLID TWO-PHASE FLOW IN A SUDDEN-EXPANSION TUBE

作　　者：李飞[1] 祁海鹰[1] 由长福[1] 包英捷[1] 

机构地区：[1]清华大学热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2006年第z1期201-204,共4页Journal of Engineering Thermophysics

基　　金：国家重点基础研究发展计划973项目资助(No.G1999022208)

摘　　要：采用PDA测量竖直向下圆管突扩流动中的气相与颗粒相运动参数,研究了小颗粒(55.2 μm)、低雷诺数(1.98×104)的稀疏流动中湍流变动的规律.结果表明,在主流区和回流区中,颗粒均削弱气相脉动,而在下游则出现增强的现象,这是由于颗粒延缓了突扩流动的发展所致.在入口段的壁面剪切区域,湍流削弱幅度与平均速度梯度呈线性关系;由于壁面的限制,回流区内的剪切作用沿流动方向逐渐增强,使得相应的各横截面内气相脉动的最大值基本保持不变,同时整体脉动程度增强.Turbulence modulation of dilute gas-solid two-phase flow with particle size of 55.2μm and low Re number 1.98×10~4in a vertical sudden-expansion tube has been measured and investigated by using PDA.The results showed that gas turbulence was weakened in main flow field due to existence of particles,while enhanced in the area downstream because of slower development of the flow jet caused by particles.In the shear zone near the wall at inlet a linear relationship between turbulence modulation and gas velocity gradient has been obtained.Furthermore,the maximum of gas turbulence intensity keeps almost constant in cross-sections where a circumfluence zone exists,while the total turbulence level increases along the flow direction,because the shear effect caused by wall in the circumfluence zone increases.

关 键 词：突扩流动 颗粒 湍流变动 PDA 

分 类 号：O359[理学—流体力学]