In this study, the thermal-hydraulic performance (THP) of the straight channel, spiral channel (SC), and spiral channel equipped with twisted-tape insert (SCT) was studied using computational fluid dynamics (CFD). The flow path length and hydraulic diameter in all channels were 1.3823 and 0.01 m, respectively, and the cross-section of the channels was selected as circular. Simulations were performed for turbulent flow regime and Reynolds Number (Re)=10000-50000. The working fluid was liquid water and the temperature of the inlet fluid and the wall channel were assumed to be constant at 298 and 353 K, respectively. According to the results, SCT had the best thermal performance but the best thermal-hydraulic performance was obtained for SC.
