ENDWALL PROFILING WITH TIP CLEARANCE FLOWS

This paper describes the design of a non-axisymmetric profiled endwall with tip clearance flow. Previous designs have assumed that the interaction between the tip clearance flow and the endwall has been negligible and this paper allows this assumption to be tested. A profiled endwall was designed, built and tested in a low speed linear cascade. The design was conducted using the Durham endwall design system and this paper provides details of the first experimental validation of this system. Overall the design system was found to perform successfully. Many other researchers have conducted endwall design, test and build exercises and the key advance here was to examine the effect of profiled endwalls on tip clearance flow. To this end a tip clearance was added to both the CFD and the cascade during the design process. The results show that even with an aspect ratio of two the endwall produces noticeable changes on the tip clearance flow. This does not however necessarily prevent a successful profiled endwall from being implemented in the cascade.