中文摘要：

以搅拌槽内单相湍流流场为研究对象，采用相位多普勒粒子分析仪（PDPA）对MK和ZHX搅拌器进行流场测试，得到不同几何参数的搅拌器在不同工况下的时均速度场分布．在此基础上计算挡板前轴向速度梯度的分布，由速度梯度的衰减确定搅拌槽内轴向对流循环的有效作用范围，并考察桨型、叶轮离底间隙和叶轮转速对轴向对流循环有效作用范围的影响．试验结果表明，在液面高度等于槽径时，轴流桨搅拌槽内轴向对流循环的有效作用范围与桨型、叶轮离底间隙和叶轮转速无关，高度为槽径的2／3．

英文摘要：

The single phase turbulent flow in a fully baffled, flat bottomed cylindrical tank of diameter equal to the liquid height, stirred with two different axial flow impellers, was investigated by using phase doppler particle analyzer （PDPA） measurement technique. The axial velocity component in fully turbu- lent flow was obtained under different operating conditions, which was used to calculate the velocity gradients. The effective volume of the axial circle flow in axially stirred tank was defined using the decay of the velocity gradients. Once the velocity gradient approaches zero, the momentum dispersion was essentially complete and the axial flow was uninfluential for axial circulation, the volume above this point was not effective. The effects of the impeller diameter, off-bottom clearance and rotational speed were investigated. Experimental results show that the effective volume of the axial circle flow in axially stirred tank for a height equal to 2/3 of the tank diameter is independent of the diameter, off-bottom clearance, speed, and type of axial impeller.