LAUSR

Abstract In the present study, heat transfer performance and flow characteristics of turbulent flow in asymmetrical corrugated tubes (ACT) are numerically and experimentally investigated. Experiments on a smooth tube and ACT were conducted for the validation of the numerical methods. Numerical simulations were then conducted to obtain an understanding of the physical behavior of thermodynamics and fluid flow in the ACT with the Reynolds number ranging from 12,000 to 66,000. Thermodynamic results between the tube side and the shell side of the ACT were then compared. Flow directions were defined as opposite, when large corrugation fillet radii ( rl ) located at the upstream or downstream. And the thermo-hydraulic performance and mechanism at the shell side, which were caused by two opposite flow directions, were presented and analyzed. The results show that, compared with the tube side of the ACT, the Nu , f , and the performance evaluation criterion ( PEC ) of the shell side in the ACT is more obvious and the maximum increment were 1.7, 1.13, and 1.26 respectively. It was also found that the value of various rl/D located at upstream does not influence on thermo-hydraulic performance. And a lower Re condition should be selected in the ACT for saving energy. While rl located at the downstream can significantly increase the overall heat transfer coefficient and decrease the Reynolds stress. The PEC was increased by 10–20% which is much more than the increase when rl was located at the upstream.