Numerical Study of Thermal-Hydraulic Performance Improvement of Enhanced Surface Tubes

Abstract

A computational fluid dynamics study was carried out to compare the thermal-hydraulic performance of two enhanced heat transfer tubes (Vipertex models 1EHT-1 and 1EHT-2) to the performance of a smooth surface tube while using R410A as the working fluid. All tubes had an equivalent internal diameter of 8.32 mm and were made of stainless steel. Analysis was performed using an SST (shear stress transport), k-omega numerical model, with the Reynolds number ranging from 15500 to 32500. There was an increase in the heat transfer coefficient and frictional pressure drop for increasing Reynolds number. Heat transfer coefficient relative error (RE) percentage for all tubes evaluated was below 10%, while for the pressure drop the RE was below 16%. Additionally, an analysis of the boundary layer in the case of the enhanced surface tube shows a fluid flow disruption and it reveals increased fluid mixing with enhanced heat transfer. Additionally, it was discovered that dimple height has more of an effect on the thermal hydraulic performance than dimple diameter. It is possible to conclude that the SST k-omega model can be used to simulate and predict heat transfer within an acceptable error tolerance, allowing the optimization of operational parameters.

Acknowledgements

The authors sincerely thank the Editor-in-Chief for his carefully editing the paper. This work was supported by the National Science Foundation of China (No.: 52076187) and Science and Technology on Thermal Energy and Power Laboratory Open Foundation of China (No.: TPL2020B01)

Additional information

Notes on contributors

Humberto Santos

Humberto Santos has bachelor’s degree and an M.S. from the Graduate Program in Energy Technology at the University of Pernambuco, Brazil. From 2013–-2014, he was a grantee of the Brazilian federal program Science Without Borders at the State University of New York College at Buffalo, working on heat transfer enhancement and PIV under the supervision of Dr. Kukulka. He was also a temporary lecturer in the Department of Mechanical and Materials Engineering at the Federal Rural University of Pernambuco. Currently, he is a temporary teacher in the Technical Education System of the State of Pernambuco, Brazil, assigned to work at ETEPAM.

Wei Li

Wei Li received his B.S. from Xi’an Jiao Tong University, and after 5 years of engineering practice in Gree Appliances in China, continued his education at Penn State (USA), where he obtained his M.S. and Ph.D. degrees with Prof. Ralph Webb in 1998. After 8 years of engineering practice serving as a director of engineering in the United States, he joined Zhejiang University as a full professor in 2006. His group has been focused on two-phase heat transfer, falling film evaporation, fouling, nanofluids, compact heat exchangers, and supercritical fuels. He is a fellow of the ASME.

David Kukulka

David J. Kukulka is a professor at the State University of New York College at Buffalo and the coordinator of the Mechanical Engineering Technology Program. He received his B.S., M.S., and Ph.D. in mechanical engineering from State University of New York at Buffalo. His research interests include thermal/fluid design and surface science studies. Many of his recent projects have been in the area of enhanced heat transfer surface design. He is a registered professional engineer in the state of New York and is a consultant for many local and national companies. Recently he has been involved in new product development for Rigidized Metals Corporation. He has published peer reviewed papers on a variety of topics and has delivered numerous keynote lectures.