利用电化学方法测量波壁管内的质量传递速率

Mass Transfer Rates Measurement in a Wavy-Walled Tube Based on Electrochemical Method

详细介绍了采用电化学方法测量质量传递速率的基本理论、测量原理及具体方法,指出了与测量精度相关的主要影响因素并提出了相应的处理措施。在此基础上将该方法成功应用于脉动流场下轴对称三维正弦波壁圆管内的质量传递测量。研究发现,在净流动雷诺数Re从50到350的范围内,当流量的振动分率P<3.0时,最佳的质量传递强化效果发生在Re=152,即过渡流发生之前。另外,活塞泵的冲程S也与质量传递速率存在紧密联系,即在S?7mm范围内,质量传递速率随S的增大而增加。结果表明,利用得到的实验数据可以清晰地判明净流动雷诺数以及脉动流的振动分率对质量传递强化效果的影响,即由电化学方法得到的实验结果可以很好地描述波壁管的质量传递性能。

The basic theory, principle and practical method of mass transfer rate electrochemical measurement are described in detail in this paper. Moreover, the paper has presented primary factors influenced on the precision and presented corresponding measurements. The successful application of this method in a three-dimensional sinusoidal wavy-walled tube for pulsatile flow shows its validity. It was found that within a range of net flow Reynolds number Re from 50 to 350 and with oscillatory fraction of the flow rate P〈3.0, the optimal mass transfer enhancement occurred （when Re is 152 at the onset of transitional flow）. Moreover, it was found that the stroke of piston pump S afforded contribution to the mass transfer enhancement. That is, when S≤7mm, mass transfer rate increases along with the increasing stroke. Based on experimental data, the influences of the net flow Reynolds number and the oscillatory fraction of flow rate on the mass transfer rates may be judged clearly. Thus, mass transfer performance in a wavy-walled tube is described clearly by electrochemical experimental results presented in this paper.