Thermo-hydraulic characteristics of turbulent flow in plain tube equipped with rotor-assembled strands
of different geometries and leads were reported, ahead of which an experiment considering a smooth
tube had been conducted to calibrate the experimental system and data reduction method. The effects
of rotor lead on heat transfer and friction characteristics were emphasized consequently. Experimental
results revealed that rotor-assembled strands of different geometries employed improved heat transfer
significantly with Nusselt number increased by 71.5–123.1% and friction factor increased by 37.4–74.8%
compared with plain tube. There into, the helical blade rotor brought the most augmentation of heat
transfer, while the blade-discreted rotor caused the largest friction loss. Generally considering, helical
blade rotor with ladders offered first-class performance sequentially followed by helical blade rotor
and blade-discreted rotor. For helical blade rotor with ladders, Nusselt number and friction factor both
increased with the decrease of rotor lead. The best thermal performance factor was achieved when helical
blade rotor with ladders was manufactured with certain parameters (rotor diameter is 22 mm, rotor lead is
150 mm). At last, the correlations of experimental results were presented based on thorough multivariate
linear normal regression method.