摘要
为研究横向射流对平板传热特性的影响,搭建了横向射流强化传热的实验台,研究了不同射流比r(0≤r≤6.69)下横向射流对加热平板对流换热效率的影响,通过加热平板表面温度的分布云图,分析了对流换热系数h的变化规律,讨论了横向射流强化传热的物理机理。结果表明:当r较小时,增加横向射流有利于强化对流换热(r=0.57时,强化传热因子Φ=8.85%);随着r的继续增大,强化传热效果不断下降(r=1.12时Φ=5.14%,r=2.23时Φ=2.34%);继续增大r值,将恶化对流换热(r=4.46时,Φ=-1.97%);随r的增大,最高温度点先后移再前移。
In order to study the influence of a transverse jet on heat transfer performance of a flat plate,an experimental setup was built up.Different jet-to-cross flow ratios（0≤r≤6.69）were explored.The temperature distributions on the heated flat plate were measured to analyze the change trend of the convective heat transfer coefficient,aiming to reveal the physical mechanism of heat transfer enhancement by a transverse jet.The results show that,the heat transfer from the flat plate was enhanced by the transverse jet when the jet-to-cross flow ratio was relatively small（the enhancing heat transfer ratioΦreached 8.85%when r was 0.57）.Increasing the jet-to-cross flow ratio resulted in lower enhancing heat transfer ratio（Φreached 5.14% when r was 1.12,andΦ was 2.34% when r was 2.23）.Further increasing the jet-to-cross flow ratio will downgrade the heat transfer effect（Φ was-1.97% when r was 4.46）.On the other hand,the location of the highest temperature point shifted to the downstream side,then shifted back to upstream side as the jet-to-cross flow ratio increased.
出处
《热力发电》
CAS
北大核心
2016年第6期11-18,25,共9页
Thermal Power Generation
基金
国家自然科学基金项目(51476145
51476146)
关键词
平板
对流换热
射流比
横向射流
强化传热
plat
convective heat transfer
jet-to-cross flow ratio
transverse jet
heat transfer enhancement
