Detailed Heat Transfer Distributions of Narrow Impingement Channels for Cast-In Turbine Airfoils
Detailed Heat Transfer Distributions of Narrow Impingement Channels for Cast-In Turbine Airfoils
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DOI：
10.1115/1.4027679
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发表时间：
2014-09
影响因子：
1.7
通讯作者：
A. Terzis;P. Ott;J. Wolfersdorf;B. Weigand;M. Cochet
中科院分区：
文献类型：
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作者：
A. Terzis;P. Ott;J. Wolfersdorf;B. Weigand;M. Cochet
目前铸造行业的能力允许整体铸造涡轮翼型的生产。由于在双壁结构中制造窄撞击腔的可行性，因此可以进一步提高撞击冷却效率。本研究利用瞬态液晶技术，对由单排5个撞击孔组成的窄腔的冷却性能进行了实验研究。在发动机实际雷诺数在10,900和85,900之间变化的范围内，获得了所有通道内表面的传热系数分布。研究了射流间距（X/D）、通道宽度（Y/D）、射流与靶板距离（Z/D）以及射流与通道中心线的偏移位置（Dy/D）等因素的影响，并组成了一个包含22种不同几何形状的测试矩阵。此外，靶板和侧壁换热率在实验不确定度范围内成功地相互关联，提供了窄冲击通道的经验换热模型。结果表明，与多射流撞击构型相似；然而，与公开文献中发现的周期性多射流撞击相关相比，可实现的传热水平约低20%。
The current capabilities of the foundry industry allow the production of integrally cast turbine airfoils. Impingement cooling effectiveness can be then further increased due to the manufacturing feasibility of narrow impingement cavities in a double-wall configuration. This study examines experimentally, using the transient liquid crystal technique, the cooling performance of narrow cavities consisting of a single row of five impingement holes. Heat transfer coefficient distributions are obtained for all channel interior surfaces over a range of engine realistic Reynolds numbers varying between 10,900 and 85,900. Effects of streamwise jet-to-jet spacing (X/D), channel width (Y/D), jet-to-target plate distance (Z/D), and jet offset position (Dy/D) from the channel centerline are investigated composing a test matrix of 22 different geometries. Additionally, the target plate and sidewalls heat transfer rates are successfully correlated within the experimental uncertainties providing an empirical heat transfer model for narrow impingement channels. The results indicate similarities with multijet impingement configurations; however, the achievable heat transfer level is about 20% lower compared to periodic multijet impingement correlations found in open literature.