Local Heat Transfer Characteristic Coincidence in Helically Coiled Tubes Under Different Heating Conditions

Abstract

The heat transfer and flow characteristics within a helically coiled tube are further investigated numerically in this work, under both uniform heating, and one-sided heating conditions. This work focuses on the local heat transfer characteristic coincidence that occurs at the innermost point of any fully developed cross-section, whereby the local Nusselt number remains constant regardless of the type of heating condition. This feature can be used to approximate the unknown heating flux for one heating condition with the known value for the other heating condition. Different parameters including flow states (Reynolds number), geometrical parameters of the helically coiled tube (curvature ratio, helical pitch), heating conditions (heat flux) and working fluid property (Prandtl number) that have significant impact on the heat transfer characteristics have been tested. The results show that the heat transfer characteristic coincidence does not change along with the variable parameters which indicates that the proposed correlation of local Nusselt numbers can be extended to a wide range of parameters.

Acknowledgments

Xuesong Li who was a visiting scholar at University of Nottingham, is now an associate professor at Jilin University.

Additional information

Funding

The authors would like to acknowledge the financial support of this work by the doctoral degree scholarship of China Scholarship Council (CSC) and the University of Nottingham, UK, and this work is also supported by Ningbo Science and Technology Bureau Technology Innovation Team project under Grant No. 2016B10010, and EU ThermaSMART project, H2020-MSCA-RISE (778104).

Notes on contributors

Wei Gong

Wei Gong is a Ph.D. student in Fluids and Thermal Engineering Research Group, Faculty of Engineering, University of Nottingham. He obtained his Bachelor degree (Thermal Energy and Power Engineering) from School of Advanced Engineering, Beihang University in 2015. His research focus is on numerical simulation of flow and heat transfer, single/multi-phase flow, droplet motion on rough surface, boiling heat transfer and lattice Boltzmann method.

Xuesong Li

Xuesong Li is an Associate Professor in Jilin University and received her Ph.D. degree (Vehicle Engineering) from Department of Automotive Engineering, Jilin University. She has been working in Hydraulic Machinery Transmission Research Institute of Automotive Engineering Institute of Jilin University, member of key technology innovation team of automobile transmission system, and postdoctoral of power engineering and engineering thermophysics of Jilin University. Her main research directions: research on the design and control of powertrain systems for new energy vehicles, hydraulic transmission for vehicles, complex turbulence and numerical simulation of multiphase flow.

Yuying Yan

Yuying Yan is Professor of Thermofluids Engineering and Head of Fluids and Thermal Engineering Research Group in Faculty of Engineering at University of Nottingham, UK. He is also L.D.S. Chair Professor and Director of Fluids and Thermal Engineering Research Center at University of Nottingham Ningbo China. He obtained B.Sc. in 1982 from Jilin University of Technology, M.Sc. in 1986 from Shanghai Institute of Mechanical Engineering, and Ph.D. in 1996 from City University, London. He started his academic position since 1998 and joined the University of Nottingham in 2004. His research covers widely ranged area of flow and heat transfer including heat transfer enhancement, phase changes, surface wetting, nanofluids and nature inspired solutions and energy efficiency.

Edward Wright

Edward Wright is a Ph.D. student in the Fluids and Thermal Engineering Research Group at the University of Nottingham. He obtained his Master’s Degree from the University of Lincoln (Lincoln, UK) in 2017 and has previously worked on various projects with Siemens Industrial Turbomachinery Ltd. The current focus of his research being on the cooling of hot end gas turbine components, primarily jet impingement and film cooling of airfoil geometries.]