Turbulent mixed convective heat transfer in a ventilated enclosure with a cylindrical/cubical heat source: a 3D analysis

ABSTRACT

A numerical study of three-dimensional turbulent mixed convection in a ventilated, thermally insulated cavity containing a hot body (cylindrical or cubical) is conducted. The cavity has an inlet and an outlet in the bottom of the left wall and at the top of the right wall, respectively. The governing equations are solved using the finite volume method, and realizable k-ε turbulence model is adopted to predict turbulence. The influence of hot body on the ventilation efficiency is analyzed in terms of pathlines, temperature field, average Nusselt number (Nu_avg), turbulence characteristics and shape of the hot body by considering different Richardson numbers ranging from Ri = 0.01 to 30. A strong dependence between the heat transfer characteristic and Richardson number is observed, and the heat body geometry plays a significant role in ventilation efficiency. The average Nusselt number is significantly affected when Ri < 1; however, it remained nearly constant for values of Ri > 10. The Nu_avg values on the cylindrical heat source are lower compared to those of the cubical heat source; however, the ventilation efficiency of the cavity including the cylindrical heat source is better.

KEYWORDS:

• Ventilation
• mixed convection
• numerical simulation
• heat source shape
• 3D flow

Acknowledgments

The financial support of the Directorate General of Scientific Research and Technological Development (DGSRTD) to the LME laboratory in conducting this research is gratefully acknowledged.

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Additional information

Notes on contributors

Djelloul Chati

Djelloul Chati is a PhD student in the Department of Mechanical Engineering at the University of Laghouat, Algeria. He completed the Engineer's degree in Mechanical Engineering, Transport & Petroleum Equipment at the University of Boumerdes, Algeria, and Master's degree in Mechanical Engineering from the University of Laghouat in 2014. His research field interest is Heat transfer and active cooling of electronic systems.

Said Bouabdallah

Said Bouabdallah is a Full Professor in the Department of Mechanical Engineering at the University of Laghouat, Algeria. He received PhD degree from the University of Constantine, Algeria in 2010. He is the head of the research team of Heat transfer & Renewable Energies in the Laboratory of Mechanics (LME). He is interested in the development of Numerical and Experimental Techniques for solving problems in Thermal Engineering and energy applications.

Badia Ghernaout

Badia Ghernaout is an Assistant Professor in the Department of Mechanical Engineering at the University of Laghouat, Algeria. She received the PhD degree from the University of Laghouat in 2015. She is interested in Heat and Mass transfer phenomena, double-diffusive convection, MHD and Computational Fluid Dynamics in thermal & Mass problems.

Ekrem Tunçbilek

Ekrem Tunçbilek is a Master’s Student and Research Assistant in Mechanical Engineering Department at Kocaeli University, Turkey. His works cover topics in Heat Transfer, Thermal management, Energy conservation and Thermal energy storage.

Müslüm Arıcı

Müslüm Arıcı is a faculty member in Mechanical Engineering Department of Kocaeli University, Turkey. He completed Diploma Course at von Karman Institute, Belgium in 2007 and received PhD degree from Kocaeli University in 2010. His research fields of interest are Numerical Heat Transfer, Computational Fluid Dynamics, Thermal management, Thermal Energy Storage, Solar Energy, and Nanofluids.

Zied Driss

Zied Driss is Full Professor in the Department of Mechanical Engineering at National School of Engineers of Sfax (ENIS). He received his Engineering Diploma in 2001, his Master Degree in 2003, his PhD in 2008 and his HDR in 2013 in Mechanical Engineering from ENIS at University of Sfax, Tunisia. He is interested on the development of numerical and experimental techniques for solving problems in mechanical engineering and energy applications. Also, his research has been focused on the interaction between Computational Fluid Dynamics (CFD) and Computational Structure Dynamics (CSD) codes. As a result of his research, he is principal or co-principal investigator on more than 180 papers in peer-reviewed journals, more than 350 communications to international conferences, 25 books and 70 books chapters. Also, he is the main inventors of 10 patents.