Flow structure, heat transfer and pressure drop in varying aspect ratio two-pass rectangular smooth channels
Flow structure, heat transfer and pressure drop in varying aspect ratio two-pass rectangular smooth channels
复制标题
DOI：
10.1007/s00231-011-0926-1
复制
发表时间：
2012-05
影响因子：
2.2
通讯作者：
Waseem Siddique;Lamyaa A. El-Gabry;I. V. Shevchuk;N. Hushmandi;T. Fransson
中科院分区：
文献类型：
--
作者：
Waseem Siddique;Lamyaa A. El-Gabry;I. V. Shevchuk;N. Hushmandi;T. Fransson
双通道通道用于许多工程系统（例如燃气轮机）中的内部冷却。流体流过弯曲路径时会受到压力和离心力，从而导致压力驱动的二次运动。这种运动有助于将冷的高动量流体从通道核心移动到侧壁，并且在通道弯曲部和出口通道中的传热中发挥重要作用。本研究利用计算流体动力学 (CFD) 研究了不同深宽比通道在不同分流器到尖端壁距离的光滑通道中的流动结构、传热增强和压降。数值模拟是在双通道光滑通道中进行的，对于各种分流器到尖端壁的距离，入口通道的纵横比 Win/H = 1:3，出口通道的 Wout/H = 1:1。结果表明，随着通道入口通道长宽比的减小，压力损失减小。分流器到尖端壁的距离 (Wel) 不仅影响压降，而且影响弯管和出口通道处的传热增强。随着分隔器到尖端壁距离的增加，增强传热的区域从出口通道的侧壁向入口通道转移。为了在通道中的传热和压降之间进行折衷，我们发现 Wel/H = 0.88 对于所研究的通道来说是最佳的。
Two-pass channels are used for internal cooling in a number of engineering systems e.g., gas turbines. Fluid travelling through the curved path, experiences pressure and centrifugal forces, that result in pressure driven secondary motion. This motion helps in moving the cold high momentum fluid from the channel core to the side walls and plays a significant role in the heat transfer in the channel bend and outlet pass. The present study investigates using Computational Fluid Dynamics (CFD), the flow structure, heat transfer enhancement and pressure drop in a smooth channel with varying aspect ratio channel at different divider-to-tip wall distances. Numerical simulations are performed in two-pass smooth channel with aspect ratio Win/H = 1:3 at inlet pass and Wout/H = 1:1 at outlet pass for a variety of divider-to-tip wall distances. The results show that with a decrease in aspect ratio of inlet pass of the channel, pressure loss decreases. The divider-to-tip wall distance (Wel) not only influences the pressure drop, but also the heat transfer enhancement at the bend and outlet pass. With an increase in the divider-to-tip wall distance, the areas of enhanced heat transfer shifts from side walls of outlet pass towards the inlet pass. To compromise between heat transfer and pressure drop in the channel, Wel/H = 0.88 is found to be optimum for the channel under study.