鼓泡床内气泡-液体两相湍流代数应力模型的数值模拟  

SIMULATION OF TURBULENT BUBBLE-LIQUID FLOWSIN BUBBLE COLUMN USING ALGEBRAIC-STRESSTWO-PHASE TURBULENCE MODEL

作　　者：周力行[1] 杨玟[1] 廉春英[1] L.S.FAN D.J.LEE 

机构地区：[1]清华大学工程力学系,北京100084 [2]俄亥俄州立大学化学工程系

出　　处：《化工学报》2002年第8期780-786,共7页CIESC Journal

基　　金：国家自然科学基金资助项目 (No .19872 0 3 9);国家重点基础研究专项经费资助项目 (No .G19990 2 2 2 0 8);美国NSF资助 .~~

摘　　要：现有的气泡 -液体两相流动的数值模拟中 ,或者不考虑湍流 ,或者仅仅考虑液体湍流 ,但是直接模拟和PIV测量结果都表明气泡由于尾迹的作用有强烈的湍流脉动 .本文首次推导和封闭了同时模拟气泡湍流脉动和液体湍流脉动的二阶矩输运方程两相湍流模型 ,并在此基础上建立了代数应力气泡 -液体两相湍流模型 .用代数应力模型模拟了二维矩形断面鼓泡床内气泡 -液体两相流动 .预报结果给出了气泡和液体两相速度场、两相Reynolds应力及湍动能分布和气泡体积分数分布 .模拟结果与PIV测量结果符合很好 ,表明了模型的合理性 .研究结果表明 ,原先静止的液体在气泡因浮力而产生的上升运动的作用下产生回流流动 ,而气泡则只有上升运动 .气泡速度始终大于液体速度 .在床内气泡湍流脉动确实始终很强烈 .液体则由于气泡的作用以及自身速度梯度产生的双重作用而发生湍流脉动 .气泡的脉动显著地大于液体的脉动 .两相湍流脉动都是各向异性的 。A second-order moment two-phase turbulence model is derived for simulating liquid-bubble two-phase turbulent fluctuations and their interaction in liquid-bubble flows. To reduce the computer memory storage and computation time, algebraic expressions of Reynolds stresses and two-phase velocity correlations are used, instead of their transport equations. The proposed model is used to simulate liquid and bubble velocities, gas volume fraction, liquid and gas Reynolds stresses and turbulent kinetic energy in a 2-D rectangular bubble column. The simulation results are in good agreement with the PIV measurement results. The studies indicate the liquid recirculation and bubble up-rising flow patterns, and anisotropic liquid and bubble normal Reynolds stresses. Bubble fluctuation is observed to be stronger than liquid fluctuation. Moreover, both liquid velocity gradient and bubble-liquid interaction are important for the generation of liquid turbulence.

关 键 词：数值模拟 鼓泡床 气液两相湍流 代数应力模型 单汽泡动力学 

分 类 号：TQ021.1[化学工程] TQ018