Three-Dimensional Mixed Convection in a Rectangular Enclosure Containing a Circular Cylinder. Issue 11 (9th March 2022)

• Record Type: Journal Article
• Authors: Cho, Hyun Woo; Park, Yong Gap; Ha, Man Yeong; Seo, Young Min
• Is Part Of: Heat transfer engineering. Volume 43:Issue 11(2022)
• Page Start: 879
• Page End: 895
• Publication Date: 2022-03-09
• Subjects: Heat -- Transmission -- Periodicals; 621.4022
• DOI: 10.1080/01457632.2021.1919970
• Languages: English
• ISSNs: 0145-7632

Abstract

Abstract: This study carried out a three-dimensional, unsteady, numerical simulation to investigate the effects of the cylinder radius, Reynolds number, three-dimensionality and unsteadiness on the mixed convection in a rectangular enclosure containing a cold circular cylinder. The variations in the cylinder radius in the range of 0.1 to 0.3 times the length of the enclosure and the Reynolds number in the range of 100 to 1000 were considered. The flow and thermal structures reached three different regimes depending on the radius of cold cylinder and Reynolds number. The patterns in the flow and thermal fields were categorized into three regimes: steady two-dimensional convection, steady three-dimensional convection, and unsteady three-dimensional convection. The temperature distribution, vortical structure, and Nusselt number for a heated bottom wall were extensively analyzed. The transition of flow regime, flow instability and the heat transfer performances were influenced by the presence of cylinder. In addition, the three-dimensional flow characteristics were quantified using orthogonal enstrophy, and the unsteady characteristics were investigated by carrying out the frequency analysis of Nusselt number. As the three-dimensionality in flow and thermal fields increases and the flow regime changes to the three-dimensional unsteady convection regime, the difference in the results of two and three-dimensional simulations also increases.