摘要
为研究脉动流中圆柱体的对流换热特性,搭建了脉动流强化传热实验台架,研究不同雷诺数(Re=563 1689)、脉动频率(f=15 59 Hz)和压力振幅(prms=25～150 Pa)的脉动流中平行圆柱体的对流换热问题,获得了相对努塞尔数的经验公式Nur(f,prms,Re)。结果揭示了低频脉动流能显著增大平行圆柱体的对流换热系数,最大相对努塞尔数可达4.5以上。此外,固定雷诺数和脉动频率时,圆柱体表面平均温度随压力振幅的增大而非线性下降,但相对努塞尔数随压力振幅的增大而线性增加;固定压力振幅和脉动频率时,相对努塞尔数随雷诺数的增大而降低。
In order to convection heat transfer of a study the characteristics of cylinder in laminar pulsating flows, an experimental setup was built. Convection heat transfer of a cylinder parallel to the direction of pulsating flows was investigated under different Reynolds numbers （Re=563-1689）, pulsating frequencies （f=-15-59 Hz） and pressure amplitudes （Prms=25-150 Pa）. An empirical formula of relative Nusselt number, i.e. Nut（f,, P^ms, Re） was obtained. Results reveal that the convection heat transfer coefficient increases obviously in pulsating flows with low pulsating frequency and high pressure amplitude. The largest relative Nusselt number can reach 4.5. In addition, the averaged surface temperature of the cylinder decreases nonlinearly with pressure amplitude in the conditions with same Reynolds number and pulsating frequency, whereas the relative Nusselt number increases linearly with pressure amplitude in the same conditions. Besides, the relative Nusselt number decreases with Reynolds number in the conditions with same pressure amplitude and pulsating frequency.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第2期86-91,16,共6页
Proceedings of the CSEE
基金
国家自然科学基金项目(51106140)
浙江省自然科学基金项目(Z1110695)~~
关键词
对流传热
脉动流
圆柱体
强化传热
convection heat transfer
pulsating flow
cylinder
heat transfer enhancement
