Engineering Journal: Effect of Dimple Protrusion Shape on The Cooling Performance of The Turbine Blade Using CFD

Tuesday, December 1, 2020

Effect of Dimple Protrusion Shape on The Cooling Performance of The Turbine Blade Using CFD

It is well understood that one way to improve a gas turbine engines power output and thermodynamic performance is to increase the temperature of the turbine inlet TIT . The inlet temperature should be gradually elevated to higher targets to pursue greater control. However, with the rise in blade inlet temperature, the heat applied to the blade increases, and the permissible melting temperature of materials increases at a slower rate. This implies that the inlet temperature of the turbine blade will exceed the melting temperature of the material by more than 500 . Thus, cooling turbine blades for a safe and long lasting operation is important. To lower the temperature of the blade content below its melting point, different internal and external cooling techniques are employed. . In recent years, in the tip region of the turbine blade, multiple augmentation devices such as fins, ribs, pins, and dimples protrusions have gained a lot of attention to enhance heat transfer. With increasing inlet temperature of the turbine, pin fin arrays cannot satisfy the need of the cooling alone. To be paired with the pin fin arrays, several more methods are also added. With slight loss of pressure, dimples and protrusions are fine options. In this present work, the numerical approach is used to investigate the influence of dimples or protrusions shape on the cooling of the turbine blade. The ANSYS 17.0 simulation software was used. The results of this study show that the , due to flow acceleration, increase in impingement area and shrinkage of the flow recirculation region within the dimple, pin fin dimple wedge duct with triangular shape dimples protrusions provides improved heat transfer enhancement.