Heat and Mass Transfer

, Volume 44, Issue 8, pp 989–998 | Cite as

Film cooling effectiveness from trenched shaped and compound holes

  • S. BaheriEmail author
  • S. P. Alavi Tabrizi
  • B. A. Jubran


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-diameter L/D = 4 and pitch-to-diameter ratio of 3.0. The effect of length-to-diameter ratio on film cooling has been also investigated using L/D in 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.


Trench Vortex Pair Film Cool Cylindrical Hole Shaped Hole 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of symbols


diameter of film-hole


turbulent kinetic energy


length-to-diameter ratio of film hole


blowing ratio = \( (\rho U)_{c} /(\rho U)_{\infty } \)


pitch-to-diameter ratio of film hole


Reynolds number


local fluid temperature


turbulence intensity


friction velocity; \( u_{ * } = {\sqrt {\tau _{w} /\rho } } \)


slot width to hole diameter ratio


coordinate in the streamwise direction


coordinate normal to the test surface


the normalized distance; \( y^{ + } = \frac{{yu_{ * } }} {\nu } \)


coordinate in the lateral direction

Greek symbols


streamwise injection angle


dissipation rate of turbulent kinetic energy


Lateral injection angle

η (eta)

adiabatic film effectiveness; \( \eta = \frac{{T - T_{\infty } }} {{T_{c} - T_{\infty } }} \)


density of the fluid


wall shear stress






free stream


  1. 1.
    Garg VK (1999) Heat transfer on a film-cooled rotating blade. NASA/CR-1999-209301 reportGoogle Scholar
  2. 2.
    Bunker RS (2005) A review of shaped hole turbine film-cooling technology. J Heat Transf 127:441–453CrossRefGoogle Scholar
  3. 3.
    Bogard DG, Thole KA (2006) Gas turbine cooling. J Propulsion Power 22(2)Google Scholar
  4. 4.
    Han JC, Teng S (2000) Effect of film-hole shape on turbine blade film cooling performance. NASA/CR–2000-209932Google Scholar
  5. 5.
    Schmidt DL, Sen B, Bogard DG (1996) Film cooling with compound angle holes: adiabatic effectiveness. J Turbomach 118:807–813CrossRefGoogle Scholar
  6. 6.
    Gritsch M, Schulz A, Wittig S (1998) Adiabatic wall effectiveness measurements of film-cooling holes with expanded exits. J Turbomach 120:549–556Google Scholar
  7. 7.
    Kim YJ, Kim SM (2004) Influence of shaped injection holes on turbine blade leading edge film cooling. Int J Heat Mass Transf 47:245–256CrossRefGoogle Scholar
  8. 8.
    Kohli A, Bogard DG (1995) Adiabatic effectiveness, thermal fields, and velocity fields for film cooling with large angle injection. In: International gas turbine and aeroengine congress and exposition, Houston, TX, June 5–8, 1995, ASME 95-GT-219Google Scholar
  9. 9.
    Schmidt DL, Sen B, Bogard DG (1994) Film cooling with compound angle holes: adiabatic effectiveness. ASME Paper 94-GT-312Google Scholar
  10. 10.
    Peterson SD, Plesniak MW (2002) Short-hole jet-in-crossflow velocity field and its relationship to film-cooling performance. Exp Fluids 33:889–898Google Scholar
  11. 11.
    Peterson SD, Plesniak MW (2004) Evolution of jets emanating from short holes into cross-flow. J Fluid Mech 503:57–91zbMATHCrossRefGoogle Scholar
  12. 12.
    Plesniak MW (2006) Noncanonical short hole jets-in-crossflow for turbine film cooling”. ASME J Appl Mech 73:474–482zbMATHCrossRefGoogle Scholar
  13. 13.
    Azzi A, Jubran BA (2003) Numerical modeling of film cooling from short length stream-wise injection holes. J Heat Mass Transf 39(4):345–353Google Scholar
  14. 14.
    Azzi A, Jubran BA (2004) Influence of leading-edge lateral injection angles on the film cooling effectiveness of a gas turbine blade. J Heat Mass Transf 40(6–7):501–508Google Scholar
  15. 15.
    Bell CM (2000) Film cooling from shaped holes. J Heat Transf 122:224–232CrossRefGoogle Scholar
  16. 16.
    Hyams DG, Leylek JH (2000) A detailed analysis of film cooling physics: Part III-Streamwise injection with shaped holes. J Turbomach 122:122–132CrossRefGoogle Scholar
  17. 17.
    Brittingham RA, Leylek JH (2000) A detailed analysis of film cooling physics: part iv-compound-angle injection with shaped holes. J Turbomach 122:133–145CrossRefGoogle Scholar
  18. 18.
    Wang T, Chintalapati S, Bunker RS, Lee CP (2000) Jet mixing in a slot. Exp Thermal Fluid Sci 22:1–17CrossRefGoogle Scholar
  19. 19.
    Lu Y, Nasir H, Ekkad SV (2005) Film cooling from a row of holes embedded in transverse slots. ASME Paper IGTI2005-68598Google Scholar
  20. 20.
    Bunker RS, Bailey JC, Lee CP, Abuaf N (2001) Method for improving the cooling effectiveness of a gaseous coolant stream, and related articles of manufacture”, US 6,234,755 B1Google Scholar
  21. 21.
    Lu Y, Ekkad S (2006) Predictions of film cooling from cylindrical holes embedded in trenches. AIAA 2006-3401, 9th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, 5–8 June 2006, San FranciscoGoogle Scholar
  22. 22.
    Lu Y, Ekkad S (2007) Understanding the effect of trenching on film cooling, Paper # HT-2007-32598. In: Proceedings of the 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference, July 8–12, 2007, Vancouver, BC, CanadaGoogle Scholar
  23. 23.
    Sargison JE, Oldfield MLG, Guo SM, Lock GD, Rawlinson AJ (2005) Flow visualization of the external flow from a converging slot-hole film cooling geometry. Exp Fluids 38:304–318CrossRefGoogle Scholar
  24. 24.
    Sargison JE, Guo SM, Oldfield MLG, Lock GD, Rawlinson AJ (2002) A converging slot-hole film cooling geometry, Part 1: Low speed flat-plate heat transfer and loss. ASME J Turbomach 124:453–460CrossRefGoogle Scholar
  25. 25.
    Sargison JE, Guo SM, Oldfield MLG, Lock GD, Rawlinson AJ (2002) A converging slot-hole film-cooling geometry. Part 2: transonic guide vane heat transfer and loss. ASME J Turbomach 124:461–471CrossRefGoogle Scholar
  26. 26.
    Oldfield MLG, Lock GD (1998) Coolant passages for gas turbine components, UK Patent Application No. 9821639.3 (1998) for the new console converging slot hole turbine film cooling hole geometry. University of Oxford, OxfordGoogle Scholar
  27. 27.
    Altorairi MS (2003) Film cooling from cylindrical holes in transverse slots. M.S. Thesis, Graduate Faculty of the Louisiana State University and Agricultural and Mechanical CollegeGoogle Scholar
  28. 28.
    Gao Z, Narzary DP, Han J (2007) Film cooling on a gas turbine blade pressure side or suction side with compound angle shaped holes. Paper # HT-2007-32098. In: Proceedings of the 2007 ASME-JSME thermal engineering summer heat transfer conference, July 8–12, 2007, Vancouver, BC, CanadaGoogle Scholar
  29. 29.
    Majumdar S, Rodi W, Zhu J (1992) Three-dimensional finite-volume method for incompressible flows with complex boundaries. J Fluids Eng 114:496–503CrossRefGoogle Scholar
  30. 30.
    Bunker RS (2002) Film cooling effectiveness due to discrete holes within transverse surface slots. GE Research&Development Center, Technical Information Series, 2001CRD204Google Scholar
  31. 31.
    Acharya S (1999) Large eddy simulations and turbulence modeling for film cooling. NACA report, 1999-209310Google Scholar
  32. 32.
    Leylek JH, Zerkle RD (1994) Discrete-jet film cooling: a comparison of computational results with experiments. ASME J Turbomach 113:358–368Google Scholar
  33. 33.
    Haven BA, Kurosaka M (1997) Kidney and anti-kidney vortices in crossflow jets. J Fluid Mech 352:27–64CrossRefGoogle Scholar
  34. 34.
    Walters DK, Leylek JH (2000) A detailed analysis of film-cooling physics: Part I-Streamwise injection with cylindrical holes. ASME J Turbomach 122:102–112CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • S. Baheri
    • 1
    Email author
  • S. P. Alavi Tabrizi
    • 1
  • B. A. Jubran
    • 2
  1. 1.Faculty of Mechanical EngineeringTabriz UniversityTabrizIran
  2. 2.Department of Aerospace EngineeringRyerson University, AIAA MemberTorontoCanada

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