Parametric study of natural convection heat transfer from an inclined rectangular cylinder embedded in a square enclosure

ABSTRACT

This paper presents the effects of aspect ratio $(0.1\le AR\le 0.7)$, Rayleigh number (${10}^2\le Ra\le {10}^6$) and inclination angle $0°\le \gamma \le 90°$ of the heated rectangular cylinder on heat transfer and fluid flow characteristics due to natural convection in air around heated rectangular cylinders of different sizes inside a cold square enclosure. Galerkin finite element method was adopted for the solution of the developed model. The walls of the enclosure were maintained at an isothermal cold temperature while the boundaries of the rectangular cylinder were kept at a constant hot temperature. The results are presented in the form of isothermal contours, stream functions, local and average Nusselt numbers. It has been found that for the range of aspect ratio and Rayleigh number considered, the rate of heat transfer increases with increasing aspect ratio and Rayleigh number. Furthermore, the orientation angle of the rectangular cylinder was found to generally augment heat transfer rate except at $AR$ value of $0.1$, where the average Nusselt number declines beyond $\gamma =45°$ for all the range of Rayleigh numbers considered. Results from the present study could be applied to nuclear reactor technology and cooling of electronic chips system optimisation.

KEYWORDS:

• Natural convection
• rectangular cylinder
• aspect ratio
• inclination angle
• square enclosure

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

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Notes on contributors

Olalekan Adebayo Olayemi

OAOlayemi is a lecturer in the Department of Aeronautical and Astronautical Engineering, Kwara State University, Malete, Kwara State, Nigeria. Engr Olayemi’s research interests involve Thermofluids, Computational fluid Dynamics and Aerodynamics. Engr Olayemi has published peer reviewed journals in his areas of interest. He is a member of the Nigeria Society of Engineers (MNSE) and a registered professional Engineer with the Council for the Regulation of Engineering in Nigeria (COREN).

Al-Farhany Khaled

Khaled Al-Farhany is an associate professor in the Department of Mechanical Engineering, University of Al-Qadisiyah, Al-Qadisiyah, Iraq. He was the head of the Mechanical Engineering Department from 2014 to 2019. He is currently the Editor-in-Chief of Al-Qadisiyah Journal for Engineering Sciences, Iraq since 2019. He was formerly an assistant lecturer in the Department of Mechanical Engineering, School of MACE, University of Manchester, Manchester, UK. Associate Professor Dr. K. Al-Farhany obtained his Bachelor of Science degree in Mechanical Engineering from the University of Mosul, Iraq, in 1999 and his Master of Science degree in Refrigeration and Air-conditioning from the University of Mosul, Iraq, in 2002. Furthermore, he obtained his Doctor of Philosophy degree in Mechanical Engineering/ Heat and Mass Transfer in Porous Media, University of Manchester, UK, in 2012. Associate Prof. Dr. Al-Farhany’s areas of interest include but not limited to, Thermo-fluids, air conditioning, Nanofluid mathematical modelling and numerical simulation. Khaled has published more than 30 papers in peer-reviewed journals in these areas. He has supervised and graduated several undergraduate, and masters students. Al-Farhany is an engineer and a registered member of the Iraqi Engineering Association, with registration number: 88 653, in the year 1999. Also. He is a Member of the Scientific and Engineering Services Bureau of The University of Al-Qadisiyah since 2003.Associate Prof. Dr. Al-Farhany has over 22 years of air conditioning /heat and mass transfer experience.