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ENHANCING FILM COOLING EFFECTIVENESS IN A GAS TURBINE END-WALL WITH A PASSIVE SEMI CYLINDRICAL TRENCH

ABSTRACT
Computational studies were carried out in the end-wall of a linear cascade, of chosen blade profile, which is provided with one row of cylindrical film cooling holes inclined at 30o to the end wall. The CO gas was used as the coolant supplied through the film holes, 2 maintaining a blowing ratio of 0.6. The film cooling hole row was positioned at the leading edge of the cascade. The mainstream fluid was air and based on its properties at the cascade inlet, the flow was found turbulent. A semi cylindrical trench was placed at two positions upstream of the cascade leading edge and three positions downstream of it. ANSYS FLUENT 15.0 was used to compute the film cooling effectiveness of the cascade endwall. Trench positioned at a distance of twice that of film hole diameter, was found to show a highest increase of area averaged effectiveness value by 30.4% over the baseline. Further to this, the influence of the trench diameter was carried out where the trench with diameter twice that of film hole diameter was found to show a 31.3% increase of cooling effectiveness over the baseline. Studies on the influence of blowing ratio showed a highest increment of cooling effectiveness value by 43.5% over the baseline a blowing ratio of 1.2.
KEYWORDS
PAPER SUBMITTED: 2017-04-12
PAPER REVISED: 2017-09-13
PAPER ACCEPTED: 2017-12-28
PUBLISHED ONLINE: 2018-02-18
DOI REFERENCE: https://doi.org/10.2298/TSCI170412001R
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2019, VOLUME 23, ISSUE Issue 3, PAGES [2013 - 2023]
REFERENCES
  1. . Ligrani, P. F. M., and Lee, J. S., Film Cooling from a single Row of Compound Angle Holes at High Blowing Ratios, International Journal of Rotating Machinery, 1996 vol. 2, pp. 259-267
  2. . Tyagi, M., and Acharya, S., Large Eddy Simulation of Film Cooling Flow From an Inclined Cylindrical Jet, ASME Journal of Turbomachinery, 2003, vol. 125, pp. 734-742.
  3. . Gritsch M., et al., Effect of Cross flows on the Discharge Coefficient of Film Cooling Holes with Varying Angles of Inclination and Orientation, ASME Journal of Turbomachinery, 2001, vol. 123, pp. 781-787.
  4. . Yong-Hui XIE, Dong-Ting YE, and Zhong-Yang SHEN., "Numerical Study On Film Cooling And Convective Heat Transfer Characteristics In The Cutback Region Of Turbine Blade Trailing Edge" Thermal Science, 2016,vol. 20,Suppl. 3, pp. S643-S649.
  5. . Bogard, D. G., and Thole, K. A., Gas Turbine Film Cooling, AIAA Journal of Propulsion and Power, 2006, vol. 22, no. 2, pp. 249-270.
  6. . Fadéla Nemdili , et al., Reynolds Stress Transport Modeling of Film Cooling at the Leading Edge of a Symmetrical Turbine Blade Model, Heat Transfer Engineering, 2008, vol. 29, no. 11, pp. 950-960.
  7. . Baheri, S. et al., Film cooling effectiveness from trenched shaped and compound holes, Heat and Mass Transfer, 2008,vol. 44, no. 8, pp. 989-998.
  8. . Colban, W. F., et al., A Film-Cooling Correlation for Shaped Holes on a Flat-Plate Surface, ASME Journal of Turbomachinery, 2011,vol. 133, pp. 01002-1- 11.
  9. . Hao Ming Li and Ibrahim Hassan, The Effects of Counter Rotating Vortex Pair Intensity on Film-Cooling Effectiveness, Heat Transfer Engineering, 2015 vol. 36, no. 16, pp. 1360-1370.
  10. . Serge KEWOU and Marcel EDOUN., "Numerical Simulation Of Convective Heat Transfer Coefficient In Channel With Corrugated Walls". Thermal Science, 2016, doi.org/10.2298/TSCI150615061K.
  11. . Xiaohong GUI and Xiange SONG, "Analysis On Three-Dimensional Flow And Heat Transfer In a Cross Wavy Primary Surface Recuperator For A MicroTurbine System" Thermal Science, 2015, Vol. 19, No. 2, pp. 489-496.
  12. . Mitra Thomas and Thomas Povey, Improving turbine endwall cooling uniformity by controlling near-wall secondary flows, Proceedings of the Institution of Mechanical Engineers, 2016,Part G: Journal of Aerospace Engineering,
  13. . Micha Prem kumar and Alagumurthi., " Conjugated Heat Transfer Analysis Of Gas Turbine Vanes Using MacCorMack's Technique" Thermal Science, Vol. 12 (2008), No. 3, pp. 65-73.
  14. . Lu, Y., Nasir, H., and Ekkad, S. V., Film Cooling From a Row of Holes Embedded in Transverse Trenches, 2005, ASME Paper No. GT2005-68598.
  15. . Scot K. Waye and David G. Bogard, High-Resolution Film Cooling Effectiveness Measurements of Axial Holes Embedded in a Transverse Trench With Various Trench Configurations, ASME Journal of Turbomachinery, 2007, vol. 129, pp. 294 - 302
  16. . Andrew R. Gratton, Measurements and Predictions of Heat Transfer for a First Vane Design, M.S. Thesis, Virginia Polytechnic Institute and State University, 2004, Blacksburg, VA.
  17. . Ravi, D., and Parammasivam, K. M., Taguchi Based Regression Analysis of End-Wall Film Cooling in a Gas Turbine Cascade with Single Row of Holes, International Journal of Turbo & Jet Engines, 2015, vol. 33, issue 3, pp. 275-292.
  18. . Ansys Fluent 15.0 User Manual documentation (2013) SAS IP, Inc.
  19. . S.V. Patankar, Numerical Heat Transfer and Fluid Flow, Hemisphere,Washington,D.C., (1980).
  20. . Vickery, W, and Hector Iacovides. Computation of gas turbine blade film cooling. 11th UK National Heat Transfer Conference. (2009).
  21. . Holman, JP 2007, ‘Experimental methods for Engineers', 7 th ed., Tata McGraw-Hill Publishing Company Limited, New Delhi.

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