Investigation of Extruded Endwall on Heat Transfer Characteristics of Channel with Staggering Pin-fins

Abstract

In order to increase turbine efficiency while retaining structural integrity, modern jet engines need an effective cooling system. Pin-fin arrays play a significant role in the internal cooling system of the turbine blade. In examining the efficacy of cooling techniques using pin-fins, the other papers focus on pin-fin configurations. In contrast, the current study is a step toward optimizing cooling cascade endwalls for better maneuvering and reservation of vortices, which leads to more considerable heat transfer near the endwalls. This study examines the flow field and heat transfer of roughed endwall in the pin-fin channel, including varieties with flat endwall and extruded endwall. The heat transfer of the channel and pressure drop properties of the extruded endwall case are quantitatively assessed to contrast with those of the flat endwalls scenario for an intake Reynolds number range of 7400 to 36000. The leading and trailing surfaces of the channel are divided into five streamwise regions to understand better how well the pin-fins and endwalls transmit heat. The results show that the new endwall construction significantly increases the high heat transfer zones around the pin-fins compared to the flat endwall scenario. In the meantime, the heat transfer of the channel to the pin-fins is enhanced by the modified endwall configuration. The redesigned endwall outperformed the basic case regarding the HTEI, rising by 15.9%. It is found that the friction factor of the new design is increased due to the narrowing channel. However, due to their much higher heat transfer capacity, the HTEI of extruded endwall is up to 41.5% higher than the HTEI of the channel with flat endwalls. These results demonstrate that the heat transfer properties of pin-fins can be significantly improved by optimizing endwall design.