A novel wavy-tape insert configuration for pipe heat transfer augmentation

In this paper, a wavy-tape insert prototype for pipe heat transfer augmentation is reported. The wavy tape is fitted in the center of a straight pipe. The flow and heat transfer characters are investigated by using computational fluid dynamics method. Full-scale simulations are conducted in thermal entrance region under isothermal boundary condition with Re ranging from 200 to 2200. The maximum overall heat transfer enhancement ratio of wavy-tape insert ups to 1.82. The swirl flow structure inside the pipe induced by the wavy-tape insert is displayed. It is observed that pairs of vortices are generated on tape flanks, which lead to the enhancement of pipe heat transfer performance. The parametric studies are performed to probe the effects of wavy-tape amplitude and width on pipe thermal-hydraulic performance. To further assess the performance of wavy-tape, the heat absorption rate of wavy-tape inserted pipe is compared with that of hollow pipe under the criterion of identical pumping power consumption, the former is 120-178% higher than the latter. On the other hand, the wavy-tape insert also competes with other types of inserts reported in previous literatures and wavy-tape insert exhibits better overall performance than others in laminar flow regime. (C) 2016 Elsevier Ltd. All rights reserved.