Skip to main content
Article thumbnail
Location of Repository

The Application of Non-Axisymmetric Endwall Contouring in a 1½ Stage, Rotating Turbine



Today gas turbines are a crucial part of the global power generation and aviation industries. Small improvements to the efficiencies of individual components within the gas flow path can, over time, lead to dramatic cost savings for the operator and at the same time improve on the amount of carbon dioxide gas emissions to the environment. One such technology is the reduction of secondary flow losses in individual blade rows within the compressor or turbine section of the gas turbine through the use of non-axisymmetric endwall contouring. By introducing subtle geometrical features onto the endwall it has been shown to be possible to improve the efficiency of individual blade rows by between 1 and 2%.\ud Few studies of these non-axisymmetric endwalls have been performed outside of the two dimensional cascade and computational domain, in addition these endwalls have been designed and tested to improve the performance of blade rows at a single design point with the off design performance having been ignored. The work presented here is aimed at investigating the use of such endwalls in a rotating blade row both at design and off-design conditions and in the presence of an upstream blade row. To this end a 1½ stage, low speed, turbine test rig has been refurbished and a new set of blades was designed to accommodate the profile of the Durham cascade at the hub. The Durham cascade is a de facto industry test case for non-axisymmetric endwall applications and therefore a generic, cascade proven, endwall design is available from the literature. The design of this new blade set is unique in that it is openly available.\ud The results include steady-state 5-hole pressure probe measurements between blade rows and computational fluid dynamics solutions to provide detailed analysis of the flow quality found within the turbine. These results are reproduced for a turbine with annular or reference endwalls and one with the generic P2 endwall design obtained from the Durham cascade.\ud Experimentally a 1.5% improvement in mixed out stage efficiency at the design condition has been found with a positive trend with increasing load. Additionally the rotor exit flows are show to be generally more uniform in the presence of profiled endwalls. The rotor torque is however reduced by as much as 3.5% and the improved flow uniformity does not always translate into a improved performance in the downstream row.\ud Insight into the overall performance and fluid mechanics of the generic non-axisymmetric endwall at a variety of load conditions has been gained and an analysis of the parameters commonly used in optimising these endwalls is discussed with Cske being clearly shown to be the superior parameter in this case. CFD evidence suggests that while the cross passage pressure gradient is reduced by endwall profiling the extent of the effect of the change in hub endwalls reaches as far as the tip. The mechanism by which the overall loss is reduced appears to be a through a change in the relative strengths of the suction and pressure side horseshoe vortices and through the delayed migration of the passage cross flow, this change the relationship of these two vortex structures; dispersing the vortex structures as they leave the row and reducing the potential for mixing losses downstream.\u

Year: 2011
OAI identifier:
Provided by: Durham e-Theses

Suggested articles


  1. (2008a) “The design of threedimensional turbine blades combined with profiled endwalls”, doi
  2. (2008b) “An experimental study of three-dimensional turbine blades combined with profiled endwalls”, doi
  3. (2000). A computational study of a novel turbine rotor partial shroud”, ASME Turbo Expo doi
  4. (2002). A design method for the profiling of end walls in turbines”, doi
  5. (2007). Aerodynamics of a low-pressure turbine airfoil at low Reynolds numbers Part 1: Steady flow measurements”, doi
  6. (1998). An AGARD working group study of 3D Navier-Stokes codes applied to single turbomachinery blade rows”,
  7. (2005). An automated instrumentation system for flow and loss measurements in a cascade”, doi
  8. (2009). An experimental study of reverse compound lean in a linear turbine cascade”,
  9. (1981). Analytic investigation of effect of end-wall contouring on stator performance”, NASA-TP-1943, E-719. 184
  10. (1982). Analytical and experimental investigation of stator endwall contouring in a small axial-flow turbine. I - Stator performance”, NASA
  11. (2001). Blade ducting for turbomachinery”,
  12. (1995). Calculations of the secondary flow in a turbine cascade”, doi
  13. (2010). Combined blowing and suction to control both midspan and endwall losses in a turbomachinery passage”, doi
  14. (1979). Comparison of transverse injection effects in annular and in straight turbine cascades”,
  15. (1999). Controlling the secondary flow in a turbine cascade by three dimensional airfoil design and endwall contouring”, doi
  16. (2001). Counter-rotating streamwise vortex formation in the turbine cascade with endwall fence”, doi
  17. (1994). Effect of combined boundary layer fences on turbine secondary flow and losses”, doi
  18. (2006). Effect of the leakage flows and upstream platform geometry on the endwall flows of a turbine cascade”, doi
  19. (2005). Effect of upstream platform geometry on the endwall flows of a turbine cascade”, doi
  20. (2010). Endwall profile design for the Durham cascade using genetic algorithms”, doi
  21. (2003). Endwall profiling for the reduction of secondary flow in turbines”,
  22. (2010). Experimental and numerical investigations of aerodynamic behaviour of a three-stage HP turbine at different operating conditions”, doi
  23. (1985). Experimental methods for engineers” MCGraw-Hill International Student Edition, 4 th Edition, 3 rd Printing,
  24. (2003). Experimental quantification of the benefits of end-wall profiling in a turbine cascade”, doi
  25. (1989). Experimentation and uncertainty analysis for engineers”, 1st ed.,
  26. (1988). Growth of secondary losses and vorticity in an axial turbine cascade”, doi
  27. (2009). High pressure turbine stage endwall profile optimisation for performance and rim seal effectiveness”, ASME Turbo Expo GT2009-59923. 188 doi
  28. (2008). Improving efficiency of a high work turbine using non-axisymmetric endwalls Part I: Endwall design and performance”, doi
  29. (2002). Improving turbine efficiency using non-axisymmetric endwalls: Validation in the multi-row environment and with low aspect ratio blading”, ASME Turbo Expo doi
  30. (2005). Investigation of a novel secondary flow feature in a turbine cascade with end wall profiling”, doi
  31. (2003). Leading edge modification effects on turbine cascade endwall loss”, doi
  32. (1993). Loss mechanisms in turbomachines”, doi
  33. (2006). Low pressure turbine design for Rolls-Royce TRENT 900 turbofan”, doi
  34. (1997). Measurements of secondary flows in a turbine cascade at off-design incidence”, doi
  35. (2009). Measurements of secondary losses in a high-lift front-loaded turbine cascade with the implementation of non-axisymmetric endwall contouring”, doi
  36. (2008). Measurements of secondary losses in a turbine cascade with the implementation of nonaxisymmetric endwall contouring”, doi
  37. (2000). Non-axisymmetric Turbine End Wall Design: Part I Three dimensional Design System”, doi
  38. (2000). Non-axisymmetric Turbine End Wall Design: Part II Experimental Validation”, doi
  39. (2001). Nonaxisymmetric turbine end wall profiling”, doi
  40. (2003). Optimizing the vane-endwall junction to reduce adiabatic wall temperature in a turbine vane passage”, ASME Turbo Expo doi
  41. (2010). Personal communications.” Ho Y-H and Lakshminarayana
  42. (2001). Prediction of turbomachinery flow physics from CFD – Review of recent computations of APPACET test cases”,
  43. (2009). Preparing for the future: Reducing gas turbine environmental impact”, IGTI Scholar Lecture, doi
  44. (2006). Profiled end-wall design using an adjoint Navier-Stokes solver”, doi
  45. (1993). Reduction in secondary flow and losses in a turbine cascade by upstream boundary layer blowing”,
  46. (1996). Reduction of secondary flow effects in a linear cascade by use of an air suction from the endwall”,
  47. (1999). Rusanov A and Yershov S doi
  48. (1998). Secondary flow decay downstream of turbine inlet guide vane with end-wall contouring”,
  49. (1984). Secondary flows and endwall boundary layers in axial turbomachines”,
  50. (2001). Secondary flows in axial turbines – A review”, doi
  51. (1990). Secondary loss generation in a linear cascade of high-turning turbine blades”, doi
  52. (1987). Secondary losses and end-wall profiling in a turbine cascade”, IMEchE C255/87,
  53. (2010). Some limitations of turbomachinery CFD”, doi
  54. (2000). Surface flow visualisation in a scaled up turbine blade passage”, doi
  55. (1996). The effect of tip clearance and tip gap geometry on the performance of a one and a half stage axial gas turbine”
  56. (1999). The exploitation of three-dimensional flow in turbomachinery design”,
  57. (1992). The influence of blade lean on turbine losses”, doi
  58. (1989). The measurement and formation of tip clearance loss”, doi
  59. (1987). The off-design performance of a low-pressure turbine cascade”, doi
  60. (1999). The secondary flow field of a turbine cascade with 3D airfoil design and endwall contouring at off design incidence”, doi
  61. (1987). Three-dimensional flow in a low-pressure turbine cascade at its design condition”, doi
  62. (1991). Three-dimensional flow near the blade/endwall junction of a gas turbine: Application of a boundary layer fence”,
  63. (1977). Three-dimensional flow within a turbine cascade passage”, doi
  64. (1996). Transition effects on secondary flows in a turbine cascade”,
  65. (2009). Turbulence model comparisons for a low pressure 1.5 stage test turbine”,
  66. (1998). Turbulent transport on the endwall in the region between adjacent turbine blades”, doi
  67. (1994). Two-equation eddy-viscosity turbulence models for engineering applications”, doi
  68. (1993). Zonal Two Equation k-ω Turbulence Models for Aerodynamic Flows”, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.