Experimental study of cooling air effect on overall cooling of laminated configuration at a turbine vane end-wall

Abstract

Turbine vane end-wall cooling management is complicated by the sophisticated cascade flow, generating the non-uniform distribution of metal temperature at end-wall surface, a negative factor of component durability. The double-wall laminated cooling has a huge potential to achieve the two-side thermal protection for end-wall, as well as the minimum cooling air amount. However, the design guidance of laminated cooling end-wall is still scarce, since that the reported flat-plate studies ignored the influence of end-wall flow. In present work, the cooling air effect on the metal overall effectiveness was extracted from the infrared thermography measurements under different cooling air flowrates, indicating that there is an utmost of cooling air consumption for the reduction of metal temperature. The two-dimensional contour of effectiveness induced by cooling air was selected as the new design principle. A case study indicated that the modified laminated cooling layout can acquire the uniform distribution of metal temperature over the entire end-wall surface. A comparison of metal overall effectiveness of original and modified end-walls revealed that in leading edge of pressure side, the novel film cooling design is more proper; and the dense layout of impingement-hole with large diameters is effective in the corner of pressure side.

Keywords

• End-wall cooling
• Laminated cooling
• Cooling air effect
• Overall effectiveness
• Guidance of design