期刊
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
卷 131, 期 11, 页码 -出版社
ASME
DOI: 10.1115/1.3154750
关键词
electronics cooling; microscale jet heat transfer; microjet; orifice pressure loss coefficient
资金
- Office of Naval Research (ONR) [GG 10919]
An investigation of the pressure drop and impingement zone heat transfer coefficient trends of a single-phase microscale impinging jet was undertaken. Microelectromechanical system (MEMS) processes were used to fabricate a device with a 67-mu m orifice. The water jet impinged on an 80-mu m square heater on a normal surface 200 mu m from the orifice. Because (of the extremely small heater area the conjugate convection-conduction heat transfer process provided an unexpected path for heat losses. A numerical simulation was use to est mate the heat losses, which were quite large. Pressure loss coefficients were much higher in the range Re-d,Re-o <500 than those predicted by available models for short orifice tubes; this behavior was likely due to the presence of the wall onto which the jet impinged. At higher Reynolds numbers, much better agreement was observed. Area-averaged heat transfer coefficients up to 80,000 W/m(2) K were attained in the range 70<1900. This corresponds to a 400 W/m(2) heat flux at a 50 degrees C temperature difference. However this impingement zone heat transfer coefficient is nearly an order-of-magnitude less than that predicted by correlations developed from macroscale jet data, and the dependence on the Reynolds number is much weaker than expected. Further investigation of microjet heat transfer is needed to explain the deviation from expected behavior [DOI: 10.1115/1.3154750]
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据