Heat transfer calculation for pipes with helical laminated swirlers

The method is reported to calculate heat transfer in pipes with laminated helical swirlers that rests upon the expansion of mean rate of pipe flow in two components, one parallel to the spiral plane (providing flow swirling) and the other, perpendicular to it (characterizing flow stall from a spiral side). A comparison of predicted Nu values for the stalling component and for the whole pipe flow has shown good agreement with the available experimental data