COMPUTATIONAL INVESTIGATIONS ON LEADING EDGE FILM COOLING OF AGTB BLADE WITH CYLINDRICAL AND TRENCHED COMPOUND ANGLE HOLES

The blade leading edge region is the most susceptible to the high temperature ablation. Film cooling strategy is often used to protect this region from being burned. In this paper, from the view point of heat flux transfer direction, the two simulated heat transfer coefficients method were compared. It was found that, for the present study, the conventional method of using same jet and main flow temperature (i.e. the isothermal method) to obtain film cooling heat transfer coefficient is not adequate and can not reflect the heat transfer phenomenon in film cooling, whereas the non-isothermal method using cooled jet and wall can reflect both the heat transfer and flow phenomenon. Subsequently, taking the real engine's AGTB blade as the object of present study, numerical approach was conducted to reveal the film cooling characteristic of AGTB blade leading edge with trenched compound angle holes, and the configuration of compound angle holes without trench was also included for comparison. And it was found that the trenched hole with compound angle can achieve better cooling and heat insulation effect in the spanwise direction.