Influence of Crossflow-Induced Swirl and Impingement on Heat Transfer in a Two-Pass Channel Connected by Two Rows of Holes
Influence of Crossflow-Induced Swirl and Impingement on Heat Transfer in a Two-Pass Channel Connected by Two Rows of Holes
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DOI：
10.1115/1.1343467
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发表时间：
2001-04
影响因子：
1.7
通讯作者：
Gautam Pamula;S. Ekkad;S. Acharya
中科院分区：
文献类型：
--
作者：
Gautam Pamula;S. Ekkad;S. Acharya
通过隔板上的两排孔连接的两通道冷却剂方形通道内，显示了详细的换热分布。强化冷却是通过冲击和横流诱导涡流相结合的方式实现的。研究了三种结构，其中横流是从一个冷却剂通道到相邻的冷却剂通道，通过一系列直孔和斜孔以及沿分隔壁放置的二维槽产生的。这些孔/槽将水流从一个通道输送到另一个通道。这通常是在常规设计中通过180度U形折弯来实现的。通道的侧壁上将显示换热分布。采用瞬变液晶技术测量了通道内的详细换热系数分布。对雷诺数在10,000~50,000范围内的三通道流雷诺数与传统180度转弯通道的计算结果进行了比较。结果表明，采用横流喷射孔的新进料系统，从第一道次到第二道次，在第二道次壁上产生了显著较高的努塞尔数。对于具有180度转弯的通道，在这些通道的第二个通道中获得的换热强化比在第二个通道中获得的传热强化大两到三倍。结果还与只有一排排气孔的通道进行了比较。
Detailed heat transfer distributions are presented inside a two-pass coolant square channel connected by two rows of holes on the divider walls. The enhanced cooling is achieved by a combination of impingement and crossflow-induced swirl. Three configurations are examined where the crossflow is generated from one coolant passage to the adjoining coolant passage through a series of straight and angled holes and a two-dimensional slot placed along the dividing wall. The holes/slots deliver the flow from one passage to another. This is typically achieved in a conventional design by a 180 deg U-bend. Heat transfer distributions will be presented on the sidewalls of the passages. A transient liquid crystal technique is applied to measure the detailed heat transfer coefficient distributions inside the passages. Results for the three-hole supply cases are compared with the results from the traditional 180 deg turn passage for three channel flow Reynolds numbers ranging between 10,000 and 50,000. Results show that the new feed system, from first pass to second pass using crossflow injection holes, produces significantly higher Nusselt numbers on the second pass walls. The heat transfer enhancements in the second pass of these channels are as much as two to three times greater than that obtained in the second pass for a channel with a 180 deg turn. Results are also compared with channels that have only one row of discharge holes.