Numerical Study of the Effect Internal Holes Shapes in Blade Turbine Cooling

Abstract

As the temperature of combustion gases is higher than the melting temperature of the turbine materials, cooling of turbine parts in a gas turbine engine is necessary. The gap between rotating turbine blades and the stationary shroud provides an unintended flow path for hot gases. Gases that flow through the tip region cause pressure losses in the turbine section and high heat loads to the blade tip. This paper numerically studies the effect of change shapes of internal cooling holes and shows the effect of cooling at the tip of blade. Also measures the effect of pressure effectiveness and temperature distribution at the tip and alone holes channels. In this study, results of change shapes of internal holes to circle, rectangle and triangle shows the circle shape is better in cooling by 45 ℃ and 125℃ when compared with rectangle and triangle shapes respectively. Streamlines results explain that they are very crowded at suction side and decreases at pressure sides and many of streamlines that passed through the gap and mixed with cooled flow. Results show also the temperature distribution alone the holes passages are reduced along them from shelf to tip and the maximum values at entrance region. Finally, the results show when the internal velocity of holes increases, the static temperature decreases in the blade.