The influence of corrugated pipes parameters on heat transfer characteristics

In order to investigate the influence mechanism of various corrugated structures on the heat transfer of continuous annular concave-convex corrugated pipes, this paper examines the influence of corrugation height (Ch=1, 1.5 and 2 mm) and corrugation width (Cw=1, 1.5 and 2 mm) on the flow pattern, turbulent kinetic energy(TKE), Nusselt number (Nu), friction coefficient (f), and performance evaluation factor (PEF). Then, the correlation equations for Nu and f are established with different corrugated structural parameters. The results show that with the increase of Ch, the vortex number, TKE, and fin the pipe increase while Nude creases. The maximum PEF is 0.90 at Ch=1 mm. However, with the increase of Cw, the vortex number and Nuin the pipe increase, while TKE and fin the pipe do not change much. The maximum PEF is 0.87 at Cw=2 mm. Therefore, for this type of corrugated pipe, one should choose a small Chand a large Cw.