The development of high-thermal-performance heat exchangers is a demand of the recent era for efficient utilization of energy sources. The present work deals with the computational fluid dynamics (CFD) analysis of flow and heat transfer in an annular pipe with square wire coil inserts in the turbulent flow regime (10500 <= Re <= 35000). A good agreement was observed for the predicted profiles of axial velocity, radial velocity, and turbulent kinetic energy using CFD and particle image velocimetry data. The effect of wire thickness and pitch and Reynolds number (Re) on vortices has been presented using the Q-criterion. The rise in friction factor and Nusselt number with inserts was observed to be 2.22 and 1.41 times higher than that in the plain annular tube. The thermal performance factor was >1 for Re < 15000 indicating that the square wire coil inserts can be used effectively for heat transfer augmentation without pumping power losses.