Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30132
Computational Investigation of Secondary Flow Losses in Linear Turbine Cascade by Modified Leading Edge Fence

Authors: K. N. Kiran, S. Anish


It is well known that secondary flow loses account about one third of the total loss in any axial turbine. Modern gas turbine height is smaller and have longer chord length, which might lead to increase in secondary flow. In order to improve the efficiency of the turbine, it is important to understand the behavior of secondary flow and device mechanisms to curtail these losses. The objective of the present work is to understand the effect of a stream wise end-wall fence on the aerodynamics of a linear turbine cascade. The study is carried out computationally by using commercial software ANSYS CFX. The effect of end-wall on the flow field are calculated based on RANS simulation by using SST transition turbulence model. Durham cascade which is similar to high-pressure axial flow turbine for simulation is used. The aim of fencing in blade passage is to get the maximum benefit from flow deviation and destroying the passage vortex in terms of loss reduction. It is observed that, for the present analysis, fence in the blade passage helps reducing the strength of horseshoe vortex and is capable of restraining the flow along the blade passage. Fence in the blade passage helps in reducing the under turning by 70 in comparison with base case. Fence on end-wall is effective in preventing the movement of pressure side leg of horseshoe vortex and helps in breaking the passage vortex. Computations are carried for different fence height whose curvature is different from the blade camber. The optimum fence geometry and location reduces the loss coefficient by 15.6% in comparison with base case.

Keywords: Boundary layer fence, horseshoe vortex, linear cascade, passage vortex, secondary flow.

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1411


[1] M. G. Rose, “Non-axisymmetric endwall profiling in the HP NGV’s of an axial flow gas turbine,” In ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition (pp. V001T01A090-V001T01A090). American Society of Mechanical Engineers, Jun 1994.
[2] K. N. Kumar, and M. Govardhan, “Secondary Flow Loss Reduction in a Turbine Cascade with a Linearly Varied Height Streamwise Endwall Fence,” International Journal of Rotating Machinery, 2011.
[3] R. E. Brachmanski, R. Niehuis, and A. Bosco, “Investigation of a Separated Boundary Layer and its Influence on Secondary Flow of a Transonic Turbine Profile,” In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition (pp. V02CT38A022-V02CT38A022). American Society of Mechanical Engineers, Jun 2014.
[4] J. D. Denton, “Loss mechanisms in turbomachines.” In ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition (pp. V002T14A001-V002T14A001). American Society of Mechanical Engineers, May 1993.
[5] L. S. Langston, “Secondary flows in axial turbines—a review,” Annals of the New York Academy of Sciences, 934(1), 11-26, 2001.
[6] C. H. Sieverding, “Recent progress in the understanding of basic aspects of secondary flows in turbine blade passages,” Journal of Engineering for Gas Turbines and Power, 107(2), 248-257, 1985.
[7] T. Germain, M. Nagel, and R. D. Baier, “Visualisation and Quantification of Secondary Flows: Application to Turbine Bladings with 3D-Endwalls,” In Paper ISAIF8-0098, Proc. of the 8th Int. Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, Lyon, July 2007.
[8] M. Govardhan, and P. K. Maharia, “Improvement of Turbine Performance by Streamwise Boundary Layer Fences,” Journal of Applied Fluid Mechanics, 5(3), 113-118, 2012.
[9] O. P. Sharma, and T. L. Butler, “Predictions of endwall losses and secondary flows in axial flow turbine cascades,” In ASME 1986 International Gas Turbine Conference and Exhibit (pp. V001T01A098-V001T01A098). American Society of Mechanical Engineers, June 1986.
[10] J. Moore, and A. Ransmayr, “Flow in a turbine cascade: Part 1—Losses and leading-edge effects,” Journal of Engineering for Gas Turbines and Power, 106(2), 400-407, 1984.
[11] S. Acharya, and G. I. Mahmood, “Turbine Blade Aerodynamics,” The Gas Turbine Handbook, 1, Chapter 4.3, pp. 364-380, 2006.
[12] T. E. Biesinger, “Secondary flow reduction techniques in linear turbine cascades,” Doctoral dissertation, Durham University, England, 1993.
[13] N. V. Aunapu, R. J. Volino, K. A. Flack, and R. M. Stoddard, “Secondary flow measurements in a turbine passage with endwall flow modification,” Journal of turbomachinery, 122(4), 651-658, 2000.
[14] N. X. Chen, Y. J. Xu, and W. G. Huang, “Straight-leaned blade aerodynamics of a turbine nozzle blade row with low span-diameter ratio,”. Journal of Thermal Science, 9(1), 51-62, 2000.
[15] W. Han, H. Huang, and Z. Wang, “Influence of blade chordwise lean on development of cascade losses,” Journal of Thermal Science, 5(4), 223-230, 1996.
[16] G. A. Zess, and K. A. Thole, “Computational design and experimental evaluation of using a leading edge fillet on a gas turbine vane,” In ASME Turbo Expo 2001: Power for Land, Sea, and Air (pp. V003T01A083-V003T01A083). American Society of Mechanical Engineers, June 2001.
[17] M. Hoeger, U. Schmidt-Eisenlohr, Gomez, SOPHIE, H. Sauer. ELMU T, and R. Müller, “Numerical simulation of the influence of a fillet and a bulb on the secondary flow in a compressor cascade,” Task Quarterly, 6(1), 25-37, 2002.
[18] S Mank, L. Duerrwaechter, M. Hilfer, R. Williams, S. Hogg, and G. Ingram, “Secondary Flows and Fillet Radii in a Linear Turbine Cascade,” In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition (pp. V02CT38A011-V02CT38A011). American Society of Mechanical Engineers, June 2014.
[19] H. Sauer, R. Muller, and K. Vogeler, “Reduction of secondary flow losses in turbine cascades by leading edge modifications at the endwall,” Journal of turbomachinery, 123(2), 207-213, 2001.
[20] G. Ingram, D. Gregory-Smith, and N. Harvey, “The benefits of turbine endwall profiling in a cascade,” Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 219(1), 49-59, 2005.
[21] G. Brennan, N. W. Harvey, M. G. Rose, N. Fomison, and M. D. Taylor, “Improving the efficiency of the trent 500-hp turbine using nonaxisymmetric end walls—part I: Turbine design,” Journal of turbomachinery, 125(3), 497-504, 2003.
[22] N. W. Harvey, M. G. Rose, M. D. Taylor, S. Shahpar, J. Hartland, and D. G. Gregory-Smith, “Non-Axisymmetric Turbine End Wall Design: Part I—Three-Dimensional Linear Design System,” In ASME International Gas Turbine and Aeroengine Congress and Exhibition (pp. V001T03A049-V001T03A049). American Society of Mechanical Engineers, June 1999.
[23] J. C. Hartland, D. G. Gregory-Smith, N. W. Harvey, and M. G. Rose, “Non-Axisymmetric Turbine End Wall Design: Part II—Experimental Validation,” In ASME International Gas Turbine and Aeroengine Congress and Exhibition (pp. V001T03A050-V001T03A050). American Society of Mechanical Engineers, June 1999.
[24] G. Ingram, D. Gregory-Smith, and N. Harvey, “Investigation of a novel secondary flow feature in a turbine cascade with end wall profiling,” Journal of turbomachinery, 127(1), 209-214, 2005.
[25] Y. J. Moon, and S. R. Koh, “Counter-rotating streamwise vortex formation in the turbine cascade with endwall fence,” Computers & fluids, 30 (4), 473-490, 2001.
[26] T. Kawai, S. Shinoki, and T. Adachi, “Secondary flow control and loss reduction in a turbine cascade using endwall fences,” JSME international journal. Ser. 2, Fluids engineering, heat transfer, power, combustion, thermophysical properties, 32(3), 375-387, 1989.
[27] T. Kawai, “Effect of Combined Boundary Layer Fences on Turbine Secondary Flow and Losses,” JSME International Journal Series B Fluids and Thermal Engineering, 37(2), 377-384, 1994.
[28] M. Govardhan, A. Rajender, and J. P. Umang, “Effect of stream wise fences on secondary flows and losses in a two-dimensional turbine rotor cascade,” Journal of Thermal Science, 15(4), 296-305, 2006.
[29] D. Dunn, G. C. Snedden, and T. W. Von Backström, “Turbulence model comparisons for a low pressure 1.5 stage test turbine,” 19th Conference of the International Society for Air Breathing Engines, Montreal, Quebec, Canada, pp 7, Sept 2009.
[30] R. Saha, “Aerodynamic Investigations of a High Pressure Turbine Vane With Leading Edge Contouring at Endwall in a Transonic Annular Sector Cascade,” Licentiate Thesis, KTH School of Industrial Engineering and Management, 2012.