چكيده به لاتين
In order to investigate the effect of turbulence intensity, Reynolds number and angle of attack on the amount of convective heat transfer of gas turbine blade surface, linear turbine cascade in the Aerodynamic and Compressible Turbomachines Laboratory of the University of Science and Technology has been used in this study. Experiments were performed on four Reynolds numbers from 100000 to 250000, five angles of attack from +8 to -8 and five turbulence intensity that changes from 1.4 to 8.3%, the effects of which have been discussed and analyzed individually .With increasing turbulence and angle of attack, the heat transfer coefficients increase with Reynolds number increase, and with increasing turbulence intensity, in each reynolds number the heat transfer is clearly increased. Also, the increase or decrease of the attack angle has partially reduced the heat transfer coefficient due to variations in velocity on the blade surface and the behavior of the boundary layer.The increase in the angle of attack, the Reynolds number, and the intensity of free flow disturbances cause an early transition, and boundary layer transition causes increasing heat transfer at once.The results of heat transfer data indicate the existence of a separation bubble region near the leading edge and on the pressure surface which was determined by conducting the flow visualization tests.
