Helically coiled tube heat exchangers (HCTHEX) have been the focus point in many experimental and numerical studies due to their compactness and high convective heat transfer coefficients on both the tube and shell sides. Previous studies have somehow established shell-side irregular behavior versus the geometrical and fluid dynamics of the coil side. At the same time, no definitive conclusion has been drawn regarding a more narrow range of characteristics of such heat exchangers (HEX). The current, more streamlined numerical analysis will shed light on a better understanding of the characteristics of such heat exchangers, following up on the previous studies by the corresponding author on the shell-side convective behavior. Deduced from an exhaustive range of simulations, a global correlation for the Nusselt number is proposed.