偏心底吹气体搅拌下冶金熔池水模型内三维湍流的实验研究

用一个圆柱形水模型模拟偏心底吹气体搅拌的冶金熔池,对模型内的三个典型剖面测量了三维速度场和湍流参数分布。方法是用二维激光多普勒测速仪在两个方向上测两次合成。面内的平行速度分布表明小流量偏心底吹熔池内的流谱为正循环流动。垂直速度分布表明,在气水两相流气泡柱附近有两个较强的圆周方向的环流,这种现象在中心底吹轴对称二维熔池流场中是不存在的。在气泡柱附近的区域内,速度模与湍动能值与较远的区域内的值相比要大得多,这就增强了这里的传热、传质和化学反应过程。在这里,气泡柱与壁面间的距离对湍流度的大小有影响,在速度值相近的情况下,较宽的区域内具有较大的湍流度值。

EXPERIMENTAL STUDY ON THREE DIMENSIONAL TURBULENT FLOW IN A WATER MODEL OF A METALLURGICAL VESSEL STIRRED BY A ECCENTRIC BOTTOM GAS INJECTION

A cylindrical water model was used to simulate a metal-lurgical vessel stirred by a eccentric bottom gas injection.The threedimensional velocity field and turbulent parameter distributions in threetypical planes were measured by usinga two component LDV from twodirectionsParallel velocity distributions show that the flow pattern in thebath stirred by eccentric bottom gas injection appears as a positive re-circulating flow.Perpendicular velocity distributions show that in thevicinity of gas-water two phase plume two stronger tangential circula-ting flows were found,this phenomenon can not be seen in centric bot-tom stirred bath in which flow is two dimensional.Much higher velocity magnitude and turbulent kinetic energy occur in the region around plume,the processes of heat transfer,mass trans-fer and chemical reaction there,for this reason,will be enhanced.Distance between wall and plume will influence on the turbulent inte-nsity,larger value can be observed in wider region,even the velocitythere is as large as in more narrow region.