Numerical investigation of heat transfer and flow characteristics of laminar flow in a tube with center-tapered wavy-tape insert

Abstract

In this study, a new type of insert, named center-tapered wavy-tape insert, which is designed from bionics based on the movement of cuttlefish, is introduced. The thermo-hydraulic performance of laminar flow in a plain tube fitted with a center-tapered wavy-tape insert under constant heat flux conditions was investigated using numerical simulation. Further, the results were compared with the conventional wavy-tape insert. It was observed that the center-tapered wavy-tape inserts have a significant influence on the reduction of flow resistance and improvement of the overall performance for producing a similar flow structure and temperature field inside the tube with a small disturbance to the core area. The optimal conditions of use of the center-tapered wavy-tape insert were studied. The considered geometric parameter combinations of the model are provided herein. The best Nusselt number could be enhanced by 5.23–8.99 times and the best performance evaluation criterion could be improved to 2.62. Then, two empirical formulas were developed for predicting Nu and f with an error band of ±14%. Finally, the numerical results were verified by the Stereo-PIV experiments.