电场对微通道中纳米流体传热的影响

Effect of electric field on heat transfer of nanofluids in microchannels

纳米流体是微通道热沉中常见的传热介质,在纳米流体中利用电泳效应可以有效提高传热效率。针对Al_(2)O_(3)-H_(2)O纳米流体,数值模拟电场分布、电场方向对微通道中纳米流体传热的影响。研究发现:在电场作用区域内,由于电泳力诱导了纳米流体的混沌对流,提高了传热效率;随着匀强电场数的增多,微通道内的强化传热效果增强;相邻2个匀强电场之间的距离越大,强化传热能力越强。

Al_(2)O_(3)-H_(2)O nanofluids arecommonly employed as a promising heat transfer medium in microchannel heat sink.Electrophoretic effect due to the external electric field can significantly improve the heat transfer efficiency.Numerical simulations for different electric field arrangements and different directions in the microchannel were carried out.The numerical results indicate that,chaotic convection can be induced by electrophoretic force in the vicinity of electric field,and the heat transfer efficiency is improved.Moreover,greater heat transfer enhancement can be obtained when more electric electrode pairs are arranged.Larger space of electrodes can result in greater heat transfer enhancement due to the larger vortex.When the interlaced electrodes are arranged,much greater enhancement can be produced.A promising design method for microchannel heat sink based on electrohydrodynamic effect can be provided for practical engineering.