Yang Weiwei,He Yaling,Tao Wenquan,Zhao Chunfeng
(State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract:Enhancing mass transfer in periodic square grooved channels by a laminar pulsating flow was studied numerically. Comprehensive research was conducted to investigate the influence of several main parameters on flow characteristics and mass transfer enhancement in the grooved channel. These parameters are Renolds number Re,Strouhal number St,pulsation amplitude A ,and geometrical characteristics of the cavity.The results obtained indicate that,due to the flow pulsation,the vortex in cavity periodically bursts and then sheds.This periodic shedding of vortices contributes to the bulk chaotic mixing of fluid which is the main factor of mass transfer enhancement.By pulsating flow, the mass transfer rate of the channel is enhanced at a large extent, especially the local mass transfer in the cavity.The enhancement of mass transfer rate increases with the Re and A.There exists an optimal Strouhal number for the greatest enhancement of mass transfer in this model, which appears to have a strong relation with the geometrical characteristics of the cavity.
Keywords:pulsating flow;enhancement of mass transfer;numerical simulation