Heat transfer enhancement by inserting a radiation-turbulence component in a wedge channel

Abstract

This study proposed the concept of coupled convective and radiative heat transfer enhancement to improve the internal cooling near turbine blade's trailing edge. An original method, which employed a radiation-turbulence component inside a wedge-shaped channel was developed. Flow and heat transfer for four channel configurations were studied numerically. The results indicated that, in condition of Re=10,000 and q = 10,000 W·m−2, compared with the existing channel's configuration merely with pin-fins and without considering radiation (Model NN), the total Nusselt number ratio of the channel using the radiation-turbulence component (Model YY) increased by 48.10 %. The maximum temperature dropped by 354.73 K and the average temperature dropped by 38.59 K. This was attributed to extension of cold surfaces for enhancement of radiative heat transfer and change of flow disturbance distribution for improvement of convective heat transfer uniformity, both of which were induced by using the radiation-turbulence component. Furthermore, the influences of the Reynolds number as well as the wall heat flux were explored. This method was proved to have an excellent self-adaptive ability, which showed that the increase of the thermal load resulted in the growth of the total Nusselt number.