Effects Of The Operating Condition And The Geometric Parameter On The Mass Transfer Rate In The Wavy-walled Tubes For Pulsatile Flow

It is an important measure to improve the efficiency of mass transfer enhancement for reducing energy consumption and environmental pollution. Previous researches about heat and mass transfer of2D and3D flow path have shown that channel geometry and flow field has a significant effect to mass transfer efficiency. In this research, the geometric parameters of wave-wall tube and the oscillatory fraction, are investigated.Five kinds of wave wall tubes with different geometric parameters are applied, and the mass transfer rate is measured by electrochemical methods under different oscillatory fraction in pulsating flow field. At the same time, the parallel experiments with two different sets of laminar flow Reynolds number are in the process. Then Reynolds number, geometric parameters of wavy-walled tubes and oscillatory fraction are forcued for the influnence of mass transfer efficiency.The experiment results show that:1, mass transfer rate increases with wave factor Fw at the same Reynolds number under steady flow field. In the pulsating flow field and the laminar flow, Reynolds number strengthening effects on the mass transfer significantly is closer to the critical Reynolds number.2, in the laminar flow near by the critical Reynolds number results in wave-walled tube of different amplitude is reduced as the mass transfer enhancement factor E increases, also has the same conclusions waves of different wavelengths within the tube wall, the same conclusions were obtained at different wavelengths of the wave-walled tube, but the result at the same Reynolds number of laminar flow is also affected by the Reynolds number.3, oscillatory fraction P values0.6,1.0and1.2, respectively, experimental results show that the effect of mass transfer rate the increase with oscillatory fraction, and mass transfer is significantly increased in the pulsatile flow with a reverse flow. This is also found with the decrease in wave factor Fw gradually emergence of the peak E, which may be due to the corresponding to the peak St number decreasing with wave factor Fw. The tube which does not appear to limit the peak is due to the ranges of measurement St number. Peaks corresponding to optimal St number does not change with oscillatory fraction.Compared with previous research conclusions, Reynolds number, geometry and Oscillatory fraction all play an important role to the final experiment results. In different geometric parameters of wave-walled tube, the laminar flow field corresponding Reynolds number is different. So in order to eliminate the influence of Reynolds number on the result, when the influence from other parameters is studied, the same flow condition of Reynolds number need be selected rather than the same Reynolds number.