Heat Transfer in a Confined Oblique Jet Impingement Configuration
Heat Transfer in a Confined Oblique Jet Impingement Configuration
复制标题
受限倾斜射流冲击配置中的传热
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Naik
中科院分区：
文献类型：
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作者：
F. Hoefler;Simon Schueren;J. Wolfersdorf;S. Naik
冲击冷却广泛应用于燃气轮机部件的冷却结构中。相对较高的局部换热速率和射流调整到特定几何形状的可能性有利于内部涡轮叶片的冷却设计。本文研究了一种受限冲击冷却结构。该组件由四个不垂直的墙壁组成，其中一个墙壁容纳两排交错倾斜的射流，每个射流冲击到不同的相邻墙壁。通过与撞击孔壁相对的两排交错排孔实现抽流。采用瞬变液晶技术对雷诺数在10,000-75,000之间的一系列射流进行了换热实验。根据空间分辨的努塞尔数以及线和面的平均值对所获得的局部传热数据进行了评估。结果包括测量通过冲击孔的流动的流量系数。对流场进行了数值模拟，作为实验的补充。这些模拟为更好地了解主要流动结构提供了信息。当Re=45000时，射流在Nusselt数高达180的对撞区内产生高换热。相反，对于相同的雷诺数，回流区的Nusselt数降至20以下。对于面积平均的Nusselt数，Nu∝Rex的相关性被发现是有效的，对每个通道墙的指数进行了轻微的修改。版权所有©2009年，阿尔斯通
Impingement cooling is widely used in cooling configurations for gas turbine components. Relatively high local heat transfer rates and the possibility of jet adjustment to specific geometries are advantageous for internal turbine blade cooling designs. In this paper a confined impingement cooling configuration is investigated. The assembly consists of four non-perpendicular walls of which one holds two rows of staggered inclined jets, each impinging on a different adjacent wall. The flow extraction is realized through two staggered rows of holes opposing the impingement holes wall. Heat transfer experiments were carried out using a transient liquid crystal technique for a series of jet Reynolds numbers between 10,000 and 75,000. The obtained local heat transfer data was evaluated regarding spatially resolved Nusselt numbers as well as line and area averaged values. The results include measurements of the discharge coefficients for the flow through the impingement holes. Numerical simulations of the flow field were carried out, complementary to the experiments. The simulations yield information for a better understanding of the main flow structures. The jets cause high heat transfer in the flow impinging regions with Nusselt numbers up to 180 for Re = 45,000. By contrast, for the same Reynolds number the Nusselt number drops below 20 in flow recirculation regions. For area-averaged Nusselt numbers, the correlation Nu ∝ Rex was found to be valid with slightly modified exponents for each passage wall.Copyright © 2009 by Alstom