Numerical analysis of electric force influence on heat transfer in a channel flow (theory based on saturated porous medium approach)
Numerical analysis of electric force influence on heat transfer in a channel flow (theory based on saturated porous medium approach)
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DOI：
10.1016/j.ijheatmasstransfer.2013.04.010
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发表时间：
2013-09
影响因子：
5.2
通讯作者：
S. I. N. Ayuttaya;Chainarong Chaktranond;P. Rattanadecho
中科院分区：
文献类型：
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作者：
S. I. N. Ayuttaya;Chainarong Chaktranond;P. Rattanadecho
本文报道了槽道流中饱和多孔介质中电极和接地布置对电驱动气流和强化换热的影响。在模拟中，进入试验段的空气入口速度和温度分别控制在0.35m/S和60°C。高电压测试范围为0-30千伏。数值结果表明，在外加电场的作用下，可以观察到剪切流动效应引起的旋流现象。电极靠近地面时，旋流小，但强度高。另外，随着电压的增大，旋流的强度也随之增大。在出现旋流的情况下，换热完全高于常规热气流的换热。与单一地面相比，多个地面效应产生的旋流在样品表面扩散得更广。这会导致样品的温度上升得更快。流动显示结果表明，烟熏技术得到的旋流流动特性与数值模拟结果吻合较好。此外，样品内的强化换热还依赖于电极和接地的布置以及样品的位置。
The present paper reports the influence of electrode and ground arrangement on electrically-driven airflow and heat transfer enhancement in a saturated porous medium placed in a channel flow. In simulations, the inlet velocity and temperature of air entering a test section are controlled at 0.35 m/s and 60 °C, respectively. High electrical voltage is tested in the range of 0–30 kV. The numerical results show+ that when electric field is applied, swirling flow caused by shear flow effect is observed. When electrode is placed near ground, swirling flow is small but it has a high strength. In addition, the strength of swirling flow is increased by increasing electrical voltage. With occurrence of swirling flow, the heat transfer is totally higher than the case of conventional hot-airflow. By comparing with a single ground, swirling flow created by multiple ground effect spreads wider over the surface of sample. This causes temperature of the sample to increase faster. It is found from flow visualization that behaviors of swirling flow obtained by smoke incense technique and simulation have a good agreement. Furthermore, enhancement of heat transfer in the sample depended on the arrangement of electrode and ground, as well as, the position of the sample.