Enhancing aerothermal performance of high-pressure turbines based on a novel tip design

Abstract

High-pressure turbines are subjected to extreme thermal loads, with the rotor tip being the most vulnerable region to thermal failure. This study presents a novel blade tip design method based on the traditional squealer tip, incorporating two new pressure-side rim modeling: (i) the Shelf tip, part of the pressure rim is shifted towards the suction section to form a vertical platform, and (ii) the Incline tip, the shelf is inclined towards the suction surface to create an inclined platform. A detailed aerothermal performance analysis reveals distinct behaviors between the two designs. Compared to the baseline squealer tip, the Shelf tip increases tip leakage and results in a 0.106 % reduction in efficiency, along with a 0.85 % increase in the average heat transfer coefficient (HTC) in the tip region. In contrast, the Incline tip reduces leakage, leading to a 0.155 % gain in efficiency, while increasing the average HTC by 3.90 %. Although the Shelf tip causes a slight decline in aerothermal performance, both designs show potential benefits when coupled with an appropriate film cooling strategy, improving the overall thermal management of the blade tip. Subsequently, the effects of geometric parameters—cavity depth and platform width—on performance were investigated. Results show that increased cavity depth and platform width degrade the Shelf tip performance but enhance that of the Incline tip. Furthermore, integrating film cooling hole arrangements with the novel tip designs significantly improves cooling efficiency. Notably, the Shelf tip with optimized film hole layout achieves a maximum relative improvement of 71.10 % in average film cooling effectiveness. This study also proposes a parametric design method for inclined blade tips and establishes an integrated framework that combines geometric modeling, aerothermal performance analysis, and cooling evaluation. The findings demonstrate that optimal aerothermal performance can be achieved by combining inclined tip geometry with film cooling, especially under conditions of increased cavity depth and platform width—offering a promising direction for advanced high-pressure turbine blade tip design.