Effect of Clearance on the Heat Transfer Characteristics of a Shroud with Squealer Tip and Tip Seal on the Turbine Blade End

In this study, the squealer tip and the plane tip with tip seal were tested in a linear cascade in order to measure the effect of the tip clearance on shroud heat transfer coefficient. The transition liquid crystal technique with a 1D semi-infinite solid assumption was used to obtain the distribution of heat transfer coefficient on the shroud surface, and three tip gaps of 1.5%, 2.0%, and 2.5% of the span were considered. The Reynolds number of the mainstream flow 6.8 ⨉ 10SUP5/SUP based on the inlet velocity of the cascade and the blade chord length. The results showed that the heat transfer coefficient on the shroud with tip seal was lower when comparing with the squealer tip case, and both tip geometries showed the lowest heat transfer coefficient at the smallest clearance.