Research on Optimal Design of Gas Turbine Blade Tip Cooling Based on Conjugate Heat Transfer Method

Abstract

Complex flow and heat transfer in the tip area of the turbine blades, as well as insufficient cooling, make the tip area more likely to be exposed to high-temperature and high-speed gas , which may lead the high thermal load problem. In order to improve working conditions of turbine blades and cool the blade tip, this paper proposed two cooling optimal schemes for blade tip based on original model. The heat transfer and flow characteristics in the tip region are analyzed based on the conjugate heat transfer (CHT) method. It is found that detailed film cooling design can effectively reduce blade tip temperature, especially from leading edge to the mid-chord region on the blade tip. In order to reduce the temperature at the trailing edge, blade tip cooling design is upgraded by improving internal cooling channel based on the optimized film cooling design. Results show that the film cooling and internal cooling channel can protect the trailing edge obviously where the thermal loads are highest. Compared with the original model, the maximum wall temperature of the tip trailing edge is reduced by 24K.