Flow response to periodic thermal forcing in a reservoir with water depth beyond the penetration depth of the solar radiation

Abstract

The present investigation is concerned with the transient response of the flow in a reservoir to diurnal heating and cooling due to heat transfer through the water surface. In this study, the maximum water depth in the reservoir is assumed to be five times the penetration depth of solar radiation. The numerical results reveal that, in the present case, the flow response to radiative heating is very weak compared with the response to surface cooling. There is also a clear time lag in the flow response to the switches of the thermal forcing. The lag time depends on the Grashof number.

Keywords:

• Diurnal thermal forcing
• periodic thermal forcing
• radiative heating
• surface cooling
• natural convection
• reservoir

Additional information

Notes on contributors

C Lei

Chengwang Lei is a Senior Lecturer in Mechanical Engineering at James Cook University. His current research is mainly focused on natural convection heat transfer, which covers topics such as natural convection induced exchange flows and mixing in natural water bodies, heat transfer through attics of buildings, and enhancement of heat transfer through a differentially heated cavity. He also has experience in both experimental and numerical modelling of vortex shedding flows over circular cylinders with applications to offshore pipelines. Since 1997, Chengwang has published over 40 refereed papers in international journals and conferences. He has been invited to review technical papers for a number of international journals including International Journal of Heat and Mass Transfer, International Journal of Numerical Methods for Heat and Fluid Flow, Journal of Heat Transfer, Numerical Heat Transfer, Heat Transfer Engineering and Journal of Fluids and Structures.

Chengwang obtained his Bachelor and Master degrees in Mechanical Engineering at Huazhong University of Science and Technology in China, and his PhD degree in Civil and Resource Engineering at The University of Western Australia. Prior to taking up a Lecturer position at James Cook University in 2003, he was an ARC Australian Postdoctoral Fellow. He also had three years industrial experience as a Mechanical Engineer in a machinery company in China. Currently, he is lecturing in areas of thermodynamics, heat and mass transfer, refrigeration and air-conditioning, and dynamics and acoustics.

J C Patterson

Professor John Patterson is a Professor of Engineering in the School of Engineering at James Cook University. Until 2006, he was Head of the School of Engineering at JCU. Prior to moving to JCU in 1996, he was Head of the Department of Environmental Engineering at the University of WA.

John’s research activities have historically covered a wide range of topics, including reservoir and estuary dynamics, mixing and water quality modelling. His current research interests lie in the area of buoyancy driven flows, with particular emphasis on thermal natural convection. He has published over 100 international journal and refereed conference papers, and has given a number of invited presentations at international conferences. He has received over $6 million in research grants from the Australian Research Council and other National Competitive Grants.