层流脉动流横掠圆柱体强化传热研究  

HEAT TRANSFER ENHANCEMENT OF A CYLINDER IN CROSS PULSATING LAMINAR FLOW

作　　者：李国能[1] 郑友取[1] 胡桂林[1] 

机构地区：[1]浙江科技学院新能源与节能技术研究所,浙江杭州310023

出　　处：《热力发电》2012年第9期19-23,共5页Thermal Power Generation

基　　金：国家自然科学基金项目(No.51106140);浙江省自然科学基金项目(No.Z1110695)

摘　　要：为研究脉动气流横掠等热流密度圆柱体的换热特性,进行了层流中雷诺数Re为85～426的脉动气流横掠高温共烧陶瓷发热管的换热试验研究。结果表明,在脉动气流的脉动频率f=30Hz、脉动振幅prms=283Pa条件下,脉动气流能大幅度提高等热流密度圆柱体的换热性能,层流中脉动流横掠等热流密度圆柱体时,圆柱体表面的温度平均值为稳定流条件下温度平均值的88.7%;脉动流中圆柱体背风面后端点与迎风面前端点的温差仅为稳定流条件下温差的16.7%;脉动流强化换热因子的区间为1.78～1.98,平均值为1.88,随雷诺数的增加而线性地降低。In order to investigate the heat transfer properties of a constant heat flux cylinder in cross pulsating flows,an experimental setup was established.The heat transfer characteristics of a high temperature co-fire ceramic(HTCC) heating tube in pulsating flows with different Reynolds numbers(Re=85~426) were explored.Pulsating frequency and RMS amplitude of the pulsating flow was 30 Hz and 283 Pa separately.Results show that,the temperature level of the cylinder surface in pulsating flows is only 88.7% of that in steady flows(in average),indicating that the pulsating flow has the capacity to increase the heat transfer coefficient significantly.On the other hand,the temperature difference between lee back point and upwind front point is only 16.7% of that in steady flows,revealing that the pulsating flow is able to decrease the temperature difference around the cylinder surface.Furthermore,results show that the pulsating flow enhances the heat transfer of the constant heat flux cylinder,and in this work,the heat transfer enhancement factor ranges from 1.78 to 1.98(1.88 in average).It decreases slightly and linearly with the increase of Reynolds number.

关 键 词：圆柱绕流 脉动气流 强化传热 圆柱体 换热 热流密度 

分 类 号：TK124[动力工程及工程热物理—工程热物理]