EFFECTS OF TIP STRUCTURE ON THE TURBINE BLADE TIP PHANTOM COOLING PERFORMANCE

Abstract

The blade tip region of the gas turbine is exposed to an extreme operating condition with a high heat load. The conventional cooling concept that places cooling holes on the tip would consume a lot of cooling air and lead to the reduction in thermal efficiency. Whereas phantom cooling was supposed to help cool the tip region without using additional cooling air. In this paper, numerical investigations were performed to forecast the tip phantom cooling effects caused by the blade ejections by implying the standard k-ω model. Then, phantom cooling performance was presented under the flat tip (FT) and the squealer tip (ST). Results show that the FT shows a better phantom cooling performance compared to the ST. The phantom cooling effects on the FT are distributed at the tip forepart and approach the pressure side (PS). Whereas, for the ST, traces of phantom cooling are barely detected on the PS rim.