For helical blade rotors

the heat transfer enhancement mechanism was theoretically analyzed. Some enhancement mechanisms involve the strengthening effects of cross section contraction

spiral flow and secondary flow.Based on the empirical equations for the plain tube and theoretical derivation

the prediction correlations for Nusselt number and pressure drop of the tube with helical blade rotors were established in the turbulent region in order to predict the influence of geometric parameters on heat transfer enhancement and resistance characteristics of rotors

including rotor lead

rotor diameter and sectional dimension.The comparison between experimental results and predicted results shows that the maximum deviations of the Nusselt number and friction factor are 7.4% and 10.1%

respectively.