0
Research Papers: Forced Convection

Numerical Investigation on Diffusion Slot Hole With Various Cross-Sectional End Shapes

[+] Author and Article Information
Bai-Tao An

Institute of Engineering Thermophysics,
Chinese Academy of Sciences,
Beijing 100190, China
e-mail: anbt@mail.etp.ac.cn

Jian-Jun Liu

Institute of Engineering Thermophysics,
Chinese Academy of Sciences,
Beijing 100190, China

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received July 14, 2016; final manuscript received March 24, 2017; published online May 9, 2017. Assoc. Editor: Jim A. Liburdy.

J. Heat Transfer 139(9), 091703 (May 09, 2017) (13 pages) Paper No: HT-16-1463; doi: 10.1115/1.4036523 History: Received July 14, 2016; Revised March 24, 2017

The diffusion hole constructed on a slot-type cross section has the potential to obtain high film cooling performance. However, the end shape of the cross section can greatly affect film cooling characteristics. This study examined eight cases of diffusion slot holes with various cross-sectional end shapes. The comparison of the eight diffusion slot holes and a typical fan-shaped hole was performed with a flat plate model using a three-dimensional (3D) steady computational fluid dynamics (CFD) method. The rectangular cross section had an aspect ratio of about 3.4. The end shape variation can be described based on sidewall contraction location, size, and form. The simulations were performed under an engine-representative condition of mainstream inlet Mach number 0.3 and turbulence intensity 5.2%. The simulated results showed that a strip separation bubble caused by inlet “jetting effect” occurs near the downstream wall of the diffusion slot hole and interacts with the diffusion flow. The different end shape of the rectangular cross section leads to different sidewall static pressure and exit velocity profiles, thereby produces three cooling effectiveness patterns, single-peak, bipeak, and tripeak patterns. The tripeak pattern produces higher cooling effectiveness and relatively uniform film coverage. The structure with moderate contraction and smooth transition on two sides of the downstream wall favors creation of a tripeak pattern. Compared with the fan-shaped hole, the discharge coefficient of diffusion slot hole is slightly small in low pressure ratio range, the pressure loss ratio has little difference.

Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Bunker, R. S. , 2005, “ A Review of Shaped Hole Turbine Film-Cooling Technology,” ASME J. Heat Transfer, 127(4), pp. 441–453. [CrossRef]
Goldstein, R. J. , Eckert, E. R. G. , and Burggraf, F. , 1974, “ Effects of Hole Geometry and Density on Three-Dimensional Film Cooling,” Int. J. Heat Mass Transfer, 17(5), pp. 595–607. [CrossRef]
Gritsch, M. , Schulz, A. , and Wittig, S. , 1998, “ Adiabatic Wall Effectiveness Measurements of Film-Cooling Holes With Expanded Exits,” ASME J. Turbomach., 120(3), pp. 549–556. [CrossRef]
Yu, Y. , Yen, C.-H. , Shih, T. I.-P. , Chyu, M. K. , and Gogineni, S. , 2002, “ Film Cooling Effectiveness and Heat Transfer Coefficient Distributions Around Diffusion Shaped Holes,” ASME J. Heat Transfer, 124(5), pp. 820–827. [CrossRef]
Dai, P. , and Lin, F. , 2011, “ Numerical Study on Film Cooling Effectiveness From Shaped and Crescent Holes,” Heat Mass Transfer, 47(2), pp. 147–154. [CrossRef]
Heneka, C. , Schulz, A. , Bauer, H. J. , Heselhaus, A. , and Crawford, M. E. , 2012, “ Film Cooling Performance of Sharp Edged Diffuser Holes With Lateral Inclination,” ASME J. Turbomach., 134(4), p. 041015. [CrossRef]
Baheri, S. , Tabrizi, S. P. A. , and Jubran, B. A. , 2008, “ Film Cooling Effectiveness From Trenched Shaped and Compound Holes,” Heat Mass Transfer, 44(8), pp. 989–998. [CrossRef]
Lu, Y. , Dhungel, A. , Ekkad, S. V. , and Bunker, R. S. , 2009, “ Effect of Trench Width and Depth on Film Cooling From Cylindrical Holes Embedded in Trenches,” ASME J. Turbomach., 131(1), p. 011003. [CrossRef]
Kusterer, K. , Bohn, D. , Sugimoto, T. , and Tanaka, R. , 2007, “ Double-Jet Ejection of Cooling Air for Improved Film Cooling,” ASME J. Turbomach., 129(4), pp. 809–815. [CrossRef]
Ely, M. J. , and Jubran, B. A. , 2009, “ A Numerical Evaluation on the Effect of Sister Holes on Film Cooling Effectiveness and the Surrounding Flow Field,” Heat Mass Transfer, 45(11), pp. 1435–1446. [CrossRef]
Ghorab, M. G. , and Hassan, I. G. , 2010, “ An Experimental Investigation of a New Hybrid Film Cooling Scheme,” Int. J. Heat Mass Transfer, 53(21–22), pp. 4994–5007. [CrossRef]
Sargison, J. E. , Guo, S. M. , Oldfield, M. L. G. , Lock, G. D. , and Rawlinson, A. J. , 2002, “ A Converging Slot-Hole Film-Cooling Geometry—Part 1: Low-Speed Flat-Plate Heat Transfer and Loss,” ASME J. Turbomach., 124(3), pp. 453–460. [CrossRef]
Leylek, J. H. , and Zerkle, R. D. , 1994, “ Discrete-Jet Film Cooling: A Comparison of Computational Results With Experiments,” ASME J. Turbomach., 116(3), pp. 358–368. [CrossRef]
Saumweber, C. , and Schulz, A. , 2012, “ Free-Stream Effects on the Cooling Performance of Cylindrical and Fan-Shaped Cooling Holes,” ASME J. Turbomach., 134(6), p. 061007. [CrossRef]
Haven, B. A. , Yamagata, D. K. , Kurosaka, M. , Yamawaki, S. , and Maya, T. , 1997, “ Anti-Kidney Pair of Vortices in Shaped Holes and Their Influence on Film Cooling Effectiveness,” ASME Paper No. 97-GT-045.
Takahashi, H. , Nuntadusit, C. , Kimoto, H. , Ishida, H. , Ukai, T. , and Takeishi, K. , 2000, “ Characteristics of Various Film Cooling Jets Injected in a Conduit,” International Symposium on Heat Transfer in Gas Turbine Systems (TURBINE-2000), Izmir, Turkey, Aug. 13–18, pp. 76–78.
Cho, H. H. , Kang, S. G. , and Rhee, D. H. , 2001, “ Heat/Mass Transfer Measurement Within a Film Cooling Hole of Square and Rectangular Cross Section,” ASME J. Turbomach., 123(4), pp. 806–814. [CrossRef]
Koç, I. , 2007, “ Experimental and Numerical Investigation of Film Cooling Effectiveness for Rectangular Injection Holes,” Aircr. Eng. Aerosp. Technol., 79(6), pp. 621–627. [CrossRef]
Okita, Y. , and Nishiura, M. , 2007, “ Film Effectiveness Performance of an Arrowhead-Shaped Film-Cooling Hole Geometry,” ASME J. Turbomach., 129(2), pp. 331–339. [CrossRef]
Bruce-Black, J. E. , Davidson, F. T. , Bogard, D. G. , and Johns, D. R. , 2011, “ Practical Slot Configurations for Turbine Film Cooling Applications,” ASME J. Turbomach., 133(3), p. 031020. [CrossRef]
Shalash, K. M. , El-Gabry, L. A. , and El-Azm, M. M. A. , 2014, “ Investigations of a Novel Discrete Slot Film Cooling Scheme,” ASME Paper No. GT2014-26019.
Bunker, R. S. , 2011, “ A Study of Mesh-Fed Slot Film Cooling,” ASME J. Turbomach., 133(1), p. 011022. [CrossRef]
An, B.-T. , Liu, J.-J. , Zhou, S.-J. , Zhang, X.-D. , and Zhang, C. , 2016, “ Film Cooling Investigation of a Slot-Based Diffusion Hole,” ASME Paper No. GT2016-56175.
Hassan, J. S. , and Yavuzkurt, S. , 2006, “ Comparison of Four Different Two-Equation Models of Turbulence in Predicting Film Cooling Performance,” ASME Paper No. GT2006-90860.
Colban, W. , Thole, K. A. , and Haendler, M. , 2007, “ Experimental and Computational Comparisons of Fan-Shaped Film Cooling on a Turbine Vane Surface,” ASME J. Turbomach., 129(1), pp. 23–31. [CrossRef]
Silieti, M. , Kassab, A. J. , and Divo, E. , 2009, “ Film Cooling Effectiveness: Comparison of Adiabatic and Conjugate Heat Transfer CFD Models,” Int. J. Therm. Sci., 48(12), pp. 2237–2248. [CrossRef]
Yang, X. , Liu, Z. , and Feng, Z. , 2015, “ Numerical Evaluation of Novel Shaped Holes for Enhancing Film Cooling Performance,” ASME J. Heat Transfer, 137(7), p. 071701. [CrossRef]
Montomoli, F. , D'Ammaro, A. , and Uchida, S. , 2013, “ Numerical and Experimental Investigation of a New Film Cooling Geometry With High P/D Ratio,” Int. J. Heat Mass Transfer, 66, pp. 366–375. [CrossRef]
Wilcox, D. C. , 1998, “ Two-Equation Models,” Turbulence Modeling for CFD, DCW Industries, La Cañada Flintridge, CA, pp. 121–201.
Grotjans, H. , and Menter, F. R. , 1998, “ Wall Functions for General Application CFD Codes,” Proceedings of the 4th Computational Fluid Dynamics Conference (ECCOMAS '98), K. D. Papailiou , ed., Wiley, Chichester, UK, pp. 1112–1117.

Figures

Grahic Jump Location
Fig. 1

Typical configurations of fan-shaped hole [14]

Grahic Jump Location
Fig. 2

Typical configurations of diffusion slot hole

Grahic Jump Location
Fig. 3

End shape cases of rectangular cross section of the diffusion slot hole (A–A plane in Fig. 2)

Grahic Jump Location
Fig. 4

Computation domain model: (a) 3D view and (b) side and top view

Grahic Jump Location
Fig. 5

Laterally averaged effectiveness of fan-shaped hole at M = 1.5 obtained by previous experimental and present numerical simulations

Grahic Jump Location
Fig. 6

Absolute velocity contours predicted by three turbulence models on hole centerline plane: (a) standard k–ε, (b) SST k–ω, and (c) RNG k–ε

Grahic Jump Location
Fig. 7

Grid independency test on laterally averaged cooling effectiveness of fan-shaped hole at M = 1.5

Grahic Jump Location
Fig. 8

Adiabatic cooling effectiveness contours of fan-shaped hole at various blowing ratios

Grahic Jump Location
Fig. 9

Adiabatic cooling effectiveness contours of eight diffusion slot holes at various blowing ratios: (a) case 1, (b) case 2, (c) case 3, (d) case 4, (e) case 5, (f) case 6, (g) case 7, and (h) case 8

Grahic Jump Location
Fig. 10

Comparison of lateral cooling effectiveness distribution on x/D = 10 at three simulated blowing ratios: (a) M = 0.5, (b) M = 1.5, and (c) M = 2.5

Grahic Jump Location
Fig. 11

Comparison of laterally averaged cooling effectiveness at three simulated blowing ratios: (a) M = 0.5, (b) M = 1.5, and (c) M = 2.5

Grahic Jump Location
Fig. 12

Comparison of spatially averaged cooling effectiveness of all simulated holes at three different blowing ratios

Grahic Jump Location
Fig. 13

Comparison of velocity contours and velocity vector streamline on hole centerline plane at blowing ratio M = 1.5: (a) fan-shaped hole and (b) diffusion slot hole case 2

Grahic Jump Location
Fig. 14

Positions of cutting planes on Z-direction and hole flow direction

Grahic Jump Location
Fig. 15

Absolute velocity contours on three Z-direction planes inside the fan-shaped hole at three different blowing ratios: (a) M = 0.5, (b) M = 1.5, and (c) M = 2.5

Grahic Jump Location
Fig. 16

Absolute velocity contours on five Z-direction planes inside the diffusion slot hole at M = 1.5: (a) case 1, (b) case 2, (c) case 3, (d) case 4, (e) case 5, (f) case 6, (g) case 7, and (h) case 8

Grahic Jump Location
Fig. 17

Static pressure contours on cutting plane 6 at M = 1.5 (viewing from the A direction in Fig. 14): (a) case 1, (b) case 2, (c) case 3, (d) case 4, (e) case 5, (f) case 6, (g) case 7, and (h) case 8

Grahic Jump Location
Fig. 18

Velocity vector streamline distribution on downstream x/D = 5 plane of fan-shaped hole (left: M = 0.5, middle: M = 1.5, and right: M = 2.5)

Grahic Jump Location
Fig. 19

Velocity vector streamline distribution on downstream x/D = 5 plane of four typical diffusion slot holes (left: M = 0.5, middle: M = 1.5, and right: M = 2.5): (a) case 1, (b) case 3, (c) case 5, and (d) case 7

Grahic Jump Location
Fig. 20

Discharge coefficients variation along with pressure ratios for all simulated hole geometries

Grahic Jump Location
Fig. 21

Pressure loss ratio variation along with blowing ratios for all simulated hole geometries

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In