Natural Convection in a Rectangular Enclosure with Colliding Boundary Layers

摘要

The movement ofthe fluid in natural convection results from the buoyancy forces imposed on thefluid when its density in the proximity of the heat transfer surface isdecreased as a result of the heating process. The objective of this paper isthe computational study of the flow initiated by natural convection. Theproblem being investigated is the colliding boundary layer in a rectangularenclosure. The dimensional governing equations are first transformed tonon-dimensional equations. The purpose of this transformation is to reduce theeffort required to make a study over a range of variables. A non-dimensionalscheme was chosen which led to improved iterative convergence for faster transients.The three dimensional analogue of the stream function-vorticity formulation wasused where the scalar vorticity was replaced by a vector and the scalar streamfunction by a vector potential. The equations were then solved using the methodof variable false transients. The results indicated that the flow region isstratified into three regions; a cold upper region, a hot region in the area ofthe confluence of hot and cold streams and a warm lower region.