The effect of top and bottom lids on natural convection inside a vertical cylinder

• Published in: International journal of heat and mass transfer 2011-01, Vol.54 (1), p.135-141
• Main Authors: Chung, Bum-Jin, Heo, Jeong-Hwan, Kim, Min-Hwan, Kang, Gyeong-Uk
• Format: Article
• Language: English
• Subjects: Analogy; Computational methods in fluid dynamics; Convection and heat transfer; Electroplating system; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Geometry effect; Instrumentation for fluid dynamics; Natural convection; Physics; Turbulent flows, convection, and heat transfer; Vertical cavity
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2010.09.059

Natural convection experiments inside a vertical cylindrical cavity were performed for Rayleigh numbers of 1.08 × 10 10–2.11 × 10 13 and for four different geometrical arrangements: both-open (pipe-shape), bottom-closed (cup-shape), top-closed (cap), and both-closed (cavity) cylinders. A copper electroplating system was employed for the measurements of heat transfer rates using analogy concept. The lids used to close top or bottom were adiabatic; i.e. inactive surfaces in the electrodeposition experiments. The bottom-closed cavity showed the highest heat transfer rates and then followed both-closed, both-open, top-closed ones in both laminar and turbulent flows. The results were in satisfactory agreements with the existing correlations developed for similar geometrical configurations and the empirical correlations were derived. The numerical simulations were carried out using the FLUENT 6.2 to explain the measured results. The analysis of the streamline and the local Nusselt number gave explanations for the observation.