90°弯管内气固两相流湍流变动实验研究  

Experimental investigation on the turbulence modification of the gas-particle flow within a 90° bend

作　　者：张洪军[1] 赵周林[1] YANG William TU Jiyuan 何春生[1] 

机构地区：[1]中国计量学院流体检测与仿真研究所,杭州310018 [2]School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Vic. 3083, Australia [3]Commonwealth Scientific and Industrial Research Organisation, Clayton South, Vic. 3169, Australia

出　　处：《水动力学研究与进展（A辑）》2010年第4期559-565,共7页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金项目(10972210);浙江省科技厅计划项目(2007C21076)

摘　　要：采用相位多普勒测速仪(PDA)对方形截面90°弯管内稀相气固两相流动进行了测量。颗粒相采用平均粒径为77μm的玻璃球,气相测量采用雾化水滴为示踪粒子。实验雷诺数Re=105(平均速度U0=10m/s)。文中对单相气体流动和气粒流中气相流动进行了分析。其中,两相流动中气相流动数据是在PDA激光散射信号后处理过程中根据颗粒尺寸进行大小颗粒(小颗粒代表气相,大颗粒代表颗粒相)分离得到的。结果发现,平均流速方面气粒流动中的气相速度较单相气体流动低,此现象产生的原因,主要是由于颗粒对连续气相介质的拖拽作用;对于湍流脉动,两相流中气相的湍流脉动比单相气体流动大,这主要是因为动能较大的颗粒相把动能传递给了气相,而这些颗粒的动能主要来源于壁面或颗粒间的碰撞。Simultaneous measurements of both the carrier gas phase and the dispersed particulate phase were carried out inside a curved 90°duct bend using Phase Doppler Anemometry （PDA）. These measurements were undertaken in order to investigate the effects of dilute turbulent particulate flows on the gas phase and vice versa. The main objective of the current study is to decipher the effect of the particles on to the gas phase at both the mean as well as at the turbulence level. Glass spheres with mean diameter of 77μm were used to represent the solid phase, while the carrier phase has a working Reynolds number of Re=1.0×10^5 （bulk velocity Uo=10m/s）. The gas phase results were analyzed as both clean gas （without any particles） and unclean gas （with particles）. The unclean gas results were separated from the particles based on their size in the post-processing step of the laser data. At the mean level, the velocities of the unclean gas phase ＇lagged＇ behind the clean gas from the mid section of the duct towards the inner bend. Almost, the same feature is observed along the vertical duct past the 90° bend. This phenomenon is mainly attributed to the effect of the particles drag on the continuous gas phase. While at the turbulence level, the unclean gas phase was seen ‘leading＇ the clean gas causing an enhancement of gas phase turbulence. This is characteristic of the energy transferred onto the gas phase from the high energy particulate phase. The particles attain these high energies due to the collisions when it experiences all along the bend section.

关 键 词：相位多普勒测速仪PDA 90°弯管 稀相气固两相流 湍流变动 

分 类 号：O357.5[理学—流体力学]