Film cooling effectiveness from trenched shaped and compound holes
Film cooling effectiveness from trenched shaped and compound holes
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DOI：
10.1007/s00231-007-0341-9
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发表时间：
2008-06
影响因子：
2.2
通讯作者：
S. Baheri;S. Tabrizi;B. Jubran
中科院分区：
文献类型：
--
作者：
S. Baheri;S. Tabrizi;B. Jubran
本文采用数值模拟的方法，对平板上以35°角喷入的一排简单孔和一排复合孔的气膜冷却进行了对比研究，这些孔有四种结构：（1）圆柱形气膜孔;（2）15°前向扩散气膜孔;（3）沟槽形圆柱形气膜孔;（4）沟槽形15°前向扩散气膜孔。所有的模拟都是在固定的密度比为1.6，吹风比为1.25，长径比L/D= 4和节径比为3.0。在长径比L/D为1 ~ 8的范围内，研究了长径比对气膜冷却的影响。使用有限体积法获得了定常、雷诺平均Navier-Stokes方程的计算解。已经发现，孔和沟槽孔的形状可以显著地影响被保护表面上的膜冷却流。此外，它已被证明，由沟槽形孔的薄膜冷却效率是高于所有其他配置无论是在展向和流向，特别是下游的喷射。此外，沟槽复合角喷射形孔产生更高的膜冷却保护比其他配置在本文中研究。沟槽孔的长径比被发现有显着的效果上的薄膜冷却的有效性和冷却剂射流的传播。
This paper presents a comparative-numerical investigation on film cooling from a row of simple and compound-angle holes injected at 35° on a flat plate with four film cooling configurations: (1) cylindrical film hole; (2) 15° forward diffused film hole; (3) trenched cylindrical film hole; (4) trenched 15° forward-diffused film hole. All simulations are at fixed density ratio of 1.6, blowing ratio of 1.25, length-to-diameterL/D= 4 and pitch-to-diameter ratio of 3.0. The effect of length-to-diameter ratio on film cooling has been also investigated usingL/Din the range of 1–8. Computational solutions of the steady, Reynolds-averaged Navier–Stokes equations have been obtained using a finite volume method. It has been found that the shape of the hole and the trenched holes can significantly affect the film cooling flow over the protected surface. Further, it has been shown that the film cooling effectiveness by trenched shaped holes is higher than all other configurations both in spanwise and streamwise specially downstream of the injection. Also, a trenched compound angle injection shaped hole produces much higher film cooling protection than the other configurations investigated in the present paper. The length-to-diameter ratio of trenched holes was found to have a significant effect on film cooling effectiveness and the spread of the coolant jets.