Thermal Performance of Twisted Heated Duct for Different Twisting Angles

Abstract

In recent years, the focus of research is mainly on the twisted pipe and ducts, as it can significantly improve heat transfer characteristics of thermal exchangers in compact and highly effective heating systems. The conducted research seeks the impact of different twisting angles (90°, 180° and 360°) on surface temperature and Nusselt number, which allow describing effectiveness of heat transfer by convection. The analysis reveals that twisted ducts generate the secondary flows that displace the thermal boundary layer and result in higher heat transfer rates. Even 90° of twisting offer an impressive enhancement when compared to plain ducts, while 180° and 360° of twisting lead to the best results.