Influence of Prandtl number, height and lateral cooling condition on laminar natural convection in a rectangular enclosure

Abstract

Laminar natural convection in a rectangular enclosure heated from bottom and cooled from top was investigated. Numerical analyses were performed using FLUENT 6.3 varying Pr from 0.2 to 2014 and height from 0.005 m to 0.04 m for either adiabatic or constant temperature lateral condition. Mass transfer experiments were also conducted using a copper sulfate electroplating system based on the analogy between heat and mass transfer for Pr of 2014, without lateral cooling, the calculated and measured results agreed with the Rayleigh-Benard correlations within 4%. For low Pr, the internal flows formed the distinct square cells. However as the Pr increased, the cell patterns became distorted due to the increased dispersion of the very thinner plumes. The additional lateral cooling enhanced the heat transfer and also varied the direction of flow in the outer cells. When the height decreased, the heat transfer increased as the number of cells increased. The heat transfer correlation was developed.