Derivation of the generalized correlations for heat transfer and friction factor for the flow in pipes with inner helical finning

In this work, new generalized correlations for predicting the friction factor and heat transfer for the flow in pipes with inner helical finning are presented. The given correlations could be applied for the single-phase Newtonian fluid flow in a wide range of Reynolds and Prandtl numbers and a broad range of geometrical parameters of inner helical finning: number of starts, fin height, relative fin spacing, and helix angle.