Heat transfer inside a horizontal circular enclosure with a heated semi-circular cylinder at different orientations

Abstract

Natural convection inside a cylindrical enclosure is important in many industrial applications. Laminar natural convective heat transfer in the annular space between heated semi-circular cylinder in a horizontal concentric cylindrical enclosure, which has relevance to cooling of electronic components, is studied in this work. Constant wall temperature (CWT) and constant wall heat flux (CWHF) boundary conditions are considered on the inner cylinder, whereas the outer cylindrical enclosure is maintained at a fixed lower temperature. The Finite Volume Method (FVM) is used for the computations. The effect of the Rayleigh number ($\mathit{\text{Ra}}={10}^2$ to ${10}^5$) and the angular orientation of the semi-circular cylinder on the convective heat transfer is investigated. The fluid flow, temperature profile, and heat flow are visualized via streamlines, isotherms, and heatlines. Further, the overall heat transfer is explained based on the local and average Nusselt number on the inner cylinder wall. The effect of the angular orientation of the inner cylinder is noticeable for $\mathit{\text{Ra}}\ge {10}^3.$ The angular orientation $\varphi$ = ${90}^{°}$ greatly enhances the heat transfer as compared to all other orientations for all $\mathit{\text{Ra}}\ge {10}^3$ for both CWT and CWHF boundary conditions. The correlation between the average Nusselt and Rayleigh numbers for a particular orientation is proposed.

Keywords:

• Constant wall heat flux
• constant wall temperature
• heatlines
• natural convection
• Rayleigh number
• semi-circular cylinder

Acknowledgment

The authors thank Dr. Pratibha Biswal for her valuable suggestions during the manuscript preparation. Furthermore, the authors acknowledge the financial support from the Ministry of Education and Ministry of Power, Government of India, through the Ucchatar Aavishkar Yojna (UAY) scheme.

Authors’ Contributions

CM: Methodology, Investigation, Writing—original draft, Writing—review and editing. SM: Conceptualization, Methodology, Writing—review and editing, Project administration, Funding acquisition.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.