Numerical study for improvement of thermal performance of gas turbine blade internal cooling in four-pass channels

This study is aims to perform three-dimensional simulation gas turbine internal cooling system for stationary and rotating mode at the middle region of four-pass smooth channels to assess fluid flow and turbulent heat transfer. The geometry of bend has been changed to U-shape turn and the guide vane in the bending region is Installed in order to enhance higher overall performance the cooling channel. The results of the governing equations are obtained using the Reynolds stress turbulence model. cooling channels are simulated in three different Reynolds numbers ranges from 20,000 to 60,000 and the rotation number of 0/13. The effect of the guide vanes on the U-shaped bend region, in addition to reducing the separation bubble area and circulation fluid in the upstream bend flow, it causes more uniform flow structure in the bend region and subsequent passage. So that the correction of bend and the use of flow guide vane to the base geometry in the case stationary of pressure drop and the coefficient of thermal performance decreases by about 13.4% and increases by 22.5%, respectively. The effect of the guide van on the amount of heat transfer in the rotating state is not noticeable, but due to the reduction of pressure drop, it increases the coefficient of thermal performance up to 9.4%.