Abstract
Numerical simulation was performed to investigate adiabatic film cooling effectiveness of cooling holes over thermal barrier coated superalloy substrate. Divergent, convergent-divergent and curved configuration of cooling holes were compared with the inclined cylindrical hole configuration. The coolant flow was strongly attached with the surface for 35º inclination. The film cooling effectiveness at different blowing ratios of 0.4, 0.8 and 1.2 was analysed. The study was carried out using realizable k-ϵ (RKE) model. The curved hole configuration provided enhanced cooling effectiveness even at 0.8 blowing ratio in comparison with other cases. The presence of curvature reduced the coolant velocity thereby preventing the detachment of jet from the surface and forming a very strong longitudinal film. The coolant jet starts detaching from the surface for blowing ratio higher than 1.2; the high momentum of the film cooling jet causes a lift off the surface. At 1.2 blowing ratio, a greater spread of coolant flow along the test surface was observed. Better film cooling effectiveness was evident at 0.8 and 1.2 blowing ratios. At 0.8, the enhancement in the overall film cooling effectiveness of divergent, convergent-divergent and curved hole configuration was about 14 %, 50 % and 59 %, respectively.
References
1. Ke Z, Wang J. Conjugate heat transfer simulations of pulsed film cooling on an entire turbine vane. Appl Thermal Eng. 2016;109:600–09.10.1016/j.applthermaleng.2016.08.132Search in Google Scholar
2. Voisey KT, Clyne TW. Laser drilling of cooling holes through plasma sprayed thermal barrier Coatings. Surf Coat Technol. 2004;176:296–306.10.1016/S0257-8972(03)00748-5Search in Google Scholar
3. Sunden B, Xie G. Gas turbine blade tip heat transfer and cooling: a literature survey. Heat Transfer Eng. 2011;31:527–54.10.1080/01457630903425320Search in Google Scholar
4. Nemdili F, Azzi A, Theodoridi G, Jubran BA. Reynolds stress transport modeling of film cooling at the leading edge of a symmetrical turbine blade model. Heat Transfer Eng. 2008;29:950–60.10.1080/01457630802186064Search in Google Scholar
5. Li X, Ren J, Jiang H. Film cooling effectiveness distribution of cylindrical hole injections at different locations on a vane end wall. Int J Heat Mass Transf. 2015;90:1–14.10.1016/j.ijheatmasstransfer.2015.06.026Search in Google Scholar
6. Park S, Jung EY, Kim SH, Sohn H-S, Cho HH. Enhancement of film cooling effectiveness using backward injection holes. Int J Thermal Sci. 2016;110:314–24.10.1115/GT2015-43853Search in Google Scholar
7. An B-T, Liu J-J, Zhang X-D, Zhou S-J, Zhang C. Film cooling effectiveness measurements of a near surface streamwise diffusion hole. Int J Heat Mass Transf. 2016;103:1–13.10.1016/j.ijheatmasstransfer.2016.07.028Search in Google Scholar
8. Yao Y, Zhang J-Z, Wang L-P. Film cooling on a gas turbine blade suction side with converging slot-hole. Int J Thermal Sci. 2013;65:267–79.10.1016/j.ijthermalsci.2012.10.004Search in Google Scholar
9. Gao Z, Narzary DP, Han J-C. Film cooling on a gas turbine blade pressure side or suction side with axial shaped holes. Int J Heat Mass Transf. 2008;51:2139–52.10.1016/j.ijheatmasstransfer.2007.11.010Search in Google Scholar
10. Lu Y, Allison D, Ekkad SV. Turbine blade showerhead film cooling: influence of hole angle and shaping. Int J Heat Fluid Flow. 2007;28:922–31.10.1016/j.ijheatfluidflow.2007.01.002Search in Google Scholar
11. Nguyen CQ, Tran NVT, Bernier BC, Ho SH, Kapat JS. Sensitivity analysis for film effectiveness on a round film hole embedded in a trench using conjugate heat transfer numerical model. ASME Turbo Expo: Power for Land, Sea and Air. 2010;4:1335–45.10.1115/GT2010-22120Search in Google Scholar
12. Ferguson JD, Walters DK, Leylek JH. Performance of turbulence models and near-wall treatments in discrete jet film cooling simulations. ASME Int Gas Turbine Aeroengine Congress Exhibition. 1998;4:1–12.10.1115/98-GT-438Search in Google Scholar
13. York WD, Leylek JH. Leading-edge film-cooling physics: part i–adiabatic effectiveness. ASME Turbo Expo: Power for Land, Sea and Air. 2002;3:1–10.10.1115/GT2002-30166Search in Google Scholar
14. Bianchini C, Facchini B, Mangani L, Maritano M. Heat transfer performance of fan-shaped film cooling holes: part ii-numerical analysis. ASME Turbo Expo: Power for Land, Sea and Air. 2010;4:1573–83.10.1115/GT2010-22809Search in Google Scholar
15. Yusop NM, Ali AH, Abdullah MZ. Computational prediction into staggered film cooling holes on convex surface of turbine blade. Int Commun Heat Mass Transfer. 2012;39:1367–74.10.1016/j.icheatmasstransfer.2012.07.021Search in Google Scholar
16. Liu C-L, Zhu H-R, Bai J-T. Effect of turbulent Prandtl number on the computation of film-cooling effectiveness. Int J Heat Mass Transf. 2008;51:6208–18.10.1016/j.ijheatmasstransfer.2008.04.039Search in Google Scholar
17. Silieti M, Divo E, Kassab AJ. The effect of conjugate heat transfer on film cooling effectiveness. Numer Heat Transfer, Part B: Fundam. 2009;56:335–50.10.1115/HT-FED2004-56234Search in Google Scholar
18. ANSYS Fluent user’s guide R17, ANSYS, Inc. 2016; Canonsburg, PA, USA.Search in Google Scholar
19. Abdelmohimen MAH. Improving film cooling from compound angle holes by adding secondary holes branched out from the main holes. Heat Mass Transfer. 2017;56:1805–15.10.1007/s00231-016-1938-7Search in Google Scholar
20. Liu C-L, Zhu H-R, Bai J-T, Xu D-C. Film cooling performance of converging slot-hole rows on a gas turbine blade. Int J Heat Mass Transf. 2010;53:5232–41.10.1016/j.ijheatmasstransfer.2010.07.036Search in Google Scholar
21. Yazid MH, Salleh H. An experiment investigation of film cooling effectiveness of sister hole of cylindrical shaped hole film cooling geometry on a flat plate surface. Appl Mechanics Mater. 2015;773:309–22.10.4028/www.scientific.net/AMM.773-774.309Search in Google Scholar
22. Lee K-D, Kim K-Y. Film cooling performance of cylindrical holes embedded in a transverse trench. Numer Heat Transfer, Part A. 2014;65:127–43.10.1080/10407782.2013.826106Search in Google Scholar
23. Ahn J, Jung IS, Lee JS. Film cooling from two rows of holes with opposite orientation angles: injectant behavior and adiabatic film cooling effectiveness. Int J Heat Fluid Flow. 2003;24:91–99.10.1016/S0142-727X(02)00200-XSearch in Google Scholar
24. Gao Z, Narzary D, Mhetras S, Han J-C. Full- coverage film cooling for a turbine blade with axial-shaped holes. J Thermophys Heat Transfer. 2008;22:50–61.10.2514/6.2007-4031Search in Google Scholar
© 2018 Walter de Gruyter GmbH, Berlin/Boston
