13-10-2017, 01:47 PM
Modern trends in gas turbine engines focus on increasing turbine inlet temperatures to reduce specific fuel consumption and increase overall engine performance. However, operation at very high temperatures reduces the lifetime of turbine blades and blades, while the permissible temperature level of the cycle is limited by the melting point of the materials. Therefore, cooling of the turbine blade is necessary to reduce the metal temperature of the blade to acceptable levels for materials that increase the thermal capacity of the motor. Due to the contribution and development of the turbine cooling systems, the turbine inlet temperature (TET) has doubled in the last 60 years.
Cooling of the turbine blade can be classified into two major sections: the internal one, where heat is removed by a variation of the convection cooling and cooling configurations, where high velocity air flows and strikes the inner surfaces of the turbine blades and blades, and the external cooling blade where cold air is injected through the cooling holes of the film on the outer blade surface to create a thin film cooling layer. In the past a wide range of internal and external cooling systems were applied; however, the aim in both cases is to keep the blade cold enough and also to ensure that temperature gradients within the blade (which can lead to thermal stresses) are maintained at an acceptable level.
Cooling of the turbine blade can be classified into two major sections: the internal one, where heat is removed by a variation of the convection cooling and cooling configurations, where high velocity air flows and strikes the inner surfaces of the turbine blades and blades, and the external cooling blade where cold air is injected through the cooling holes of the film on the outer blade surface to create a thin film cooling layer. In the past a wide range of internal and external cooling systems were applied; however, the aim in both cases is to keep the blade cold enough and also to ensure that temperature gradients within the blade (which can lead to thermal stresses) are maintained at an acceptable level.