An experimental and numerical study on the liquid cooling of a gas turbine blade

Abstract

In this paper, two kinds of internal liquid kerosene and one film cooling channels are designed for a static blade of turbine engine. The cooling efficiency is studied through numerical and experimental approaches. Two internal liquid cooling channels include a regular-sized(di = 4 mm) and a micro-channel(di = 0.8 mm). Regular sized cooling structure is three U-shaped channels. Higher heat transfer coefficient is observed in the area near the inner wall before the elbow and near the outer wall after the elbow. The regular sized channel cannot be designed approaching the leading edge of the blade due to the larger channel diameter. It will lead to poor cooling efficiency at the leading edge. The micro channel cooling structure can be mounted closer to the leading edge because of its smaller diameter. It covers a wide area and can be evenly arranged on the pressure and suction surfaces of the blade. For the film cooling structure, it shows that the film cooling method can effectively reduce the leading edge temperature when the blowing ratio is greater than 1.3. The optimal blowing ratio for this blade is about 2.5. Experiments are carried out under high temperature conditions (1000 K). Experiment results show that the micro channel cooling structure can reduce the blade temperature by more than 230 K, and the error between simulation and experiment is less than ± 10 %.