带滴状纵向涡发生器的矩形微通道内流动与传热性能的数值研究  

Numerical Study on Flow and Heat Transfer Performance in Rectangular Microchannel with Drop-shaped Longitudinal Vortex Generators

作　　者：张湘敏 田茂诚[1] 刘斐[1] 于德涛 Zhang Xiangmin;Tian Maocheng;Liu Fei;Yu Detao(School of Energy and Power Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]山东大学能源与动力工程学院,济南250061

出　　处：《水动力学研究与进展（A辑）》2023年第3期399-408,共10页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金(52176080)。

摘　　要：新型滴状纵向涡流发生器(DLVG)结合了矩形和椭圆形结构的优点,在微通道强化传热方面具有重要意义。该文数值模拟了雷诺数(Re)为400~1200范围内带有DLVG的三维微通道模型的流动和传热性能,并与带有矩形小翼纵向涡发生器(RWVG)的通道进行了对比。结果表明,DLVG比RWVG具有更好的局部传热强化能力。并讨论了Re、前端半径(R_(1))、攻角(β)和渐变纵向间距(d_(1)和d_(2))对强化传热的影响。结果表明,不同Re下,综合换热性能(PEC)最佳的前端半径R_(1)不同,R_(1)=0.04 mm的通道在Re=1200时PEC最佳,可达到1.41。与光滑微通道相比,努塞尔数Nu提高了55.15%;与RWVG通道相比,Nu最大增加了7.6%,PEC最大增加了5.2%。随着Re的增大,β越大,Nu越高,f越小,PEC越好,攻角75°时的PEC最高为1.47。纵向涡流发生器前后间距相同时的换热性能最差,d_(1)和d_(2)为5.4 mm和4.5 mm的通道Nu最大以及PEC最佳,在不同Re下,比等纵向间距通道的PEC增加了1.41%~4.55%。变量Re和β的改变对PEC增长率平均值的影响更敏感。The novel drop-shaped longitudinal vortex generator(DLVG)combines the advantages of rectangular and elliptical structures,which offer great significance in microchannel heat transfer enhancement.In this research,the flow and heat transfer performance of a microchannel 3D model with DLVG in the Reynolds number(Re)range of 400~1200 is numerically simulated and compared with that of a channel with the rectangular winglet longitudinal vortex generator(RWVG).The findings indicate that DLVG has a better capacity to increase local heat transfer than RWVG.The effects of Re,front-end radius(R_1),attack angle(β),and gradient longitudinal spacing(d_1,d_2)on the heat transfer enhancement are discussed.The results show that the optimal front-end radius R_1 for the comprehensive heat transfer performance(PEC)varies for different Re,the PEC of the channel with R_1=0.04 mm is the best at Re=1200,which can reach 1.41.Compared with the smooth microchannel,the Nusselt number Nu increases by 55.15%.Nu increases by 7.6%and PEC increases by 5.2%when compared to the RWVG channel.With the increase of Re,the larger theβ,the higher the Nu,the lower the f,and the better PEC,and PEC is up to 1.47 at 75°angle of attack.The heat transfer performance of the longitudinal vortex generator is the worst when the front and rear spacing is the same.The Nu of the channel with d_1 and d_2 of 5.4 mm and 4.5 mm respectively is the greatest,and the PEC is the highest,it is 1.41%~4.55%higher than that of the equal longitudinal spacing channel under various Re.The average of PEC growth rate is more sensitive to changes in the factors Re andβ.

关 键 词：微通道 滴状结构 纵向涡流发生器 数值模拟 流动换热性能 

分 类 号：TK124[动力工程及工程热物理—工程热物理]