Heat transfer enhancement in a triple-layered turbine blade internal cooling channel

Abstract

An effective measure of enhancing the coupled convection and radiation in the turbine blade internal cooling channel is developed. A triple-layered channel is presented for the first time to further improve the flow organization to suppress the negative effect of secondary flows induced by rotation as well as extend cold surfaces for radiation. Explorations of flow and coupled heat transfer are executed numerically for various channel models. The results manifest that, heat transfer is markedly improved with the triple-layered channel. The highest comprehensive thermal performance is achieved when employing the triple-layered channel with smooth surfaces and ribs (Model 3SW), which can increase the total Nusselt number ratio by 105.78 % and performance evaluation criterion by 18.75 %, comparing with the existing Model 1 N. Besides, the average and maximum wall temperature drop by 54.26 K and 293.02 K, respectively. In addition, the triple-layered channel is demonstrated to have the ability to reduce rotational effects on heat transfer uniformity. The heat transfer difference between the leading and trailing walls induced by the Coriolis force is restricted. It also has the self-adaptive ability to increase the degree of heat transfer enhancement when thermal load increases.