Endwall heat transfer and pressure loss measurements in staggered arrays of adiabatic pin fins

Abstract

In many applications, pin fin arrays are used for heat transfer enhancement. Due to additionally induced turbulence in the flow field, the heat transfer is increased. This study focuses on different pin fin arrays with thermally inactive pin fins. The configurations include short and long elements. Transient experiments are conducted to determine the heat transfer characteristics on the endwall. Therefore, the transient liquid crystal technique is applied to obtain locally resolved heat transfer data. Three configurations with a relative spacing of 2.5⩽S/D⩽5 and aspect ratio of 2⩽H/D⩽4 are investigated. Hereby, the Reynolds number of the air flow, based on the pin fin diameter, varies from 3·103 to 3·104. First, an overview of the experimental setup and the transient measurement technique is given. Then, heat transfer results on the endwall are presented in terms of Nusselt number. Finally, the pressure drop is evaluated by the friction factor and the thermal performance of the investigated configurations is discussed.