Application and improvement of gas turbine blades film cooling

Abstract

A higher thermal efficiency and a larger power generation of aircraft turbine engine have long been pursued by researchers. To achieve this target, the turbine inlet temperature must be raised. Gas turbines are operated at around 1800 °C now and definitely will be higher than 2000 °C someday. This temperature induces excessive thermal stresses on the turbine blade, thus the possibility of thermal failure is enhanced. The blade leading edge is the area with the highest thermal load in a gas turbine, and the film cooling is the most effective method to protect the blade from ablating. The flow structure complexity of coolant ejected from the film holes is determined by the blowing ratio, distribution of the film holes, direction of the film holes and the pressure gradient in the main stream direction. This paper analyzed the use of film cooling in gas turbine blades, as well as analyzed ways of raising its effectiveness.