| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 763196 | Computers & Fluids | 2007 | 21 Pages |
Steady, laminar natural convection in a two-dimensional enclosure with three flat and one wavy walls is numerically investigated. The top wall is heated with a sinusoidal temperature profile. The other three walls, including the wavy wall, are maintained at constant low temperature. Air is considered as the working fluid. This problem is numerically solved by SIMPLE algorithm with deferred QUICK scheme in non-orthogonal curvilinear co-ordinates. The mesh generation has been done by solving the partial differential equation with grid control functions. Tests are carried out for wave amplitudes 0.0–0.10 in steps of 0.01 and Rayleigh numbers 100–106 while the Prandtl number is kept constant. The number of undulations considered are one, two or three.The effect of the various parameters (Rayleigh number, amplitude of undulation and number of undulations) on the flow pattern and heat transfer has been studied. The heat transfer mode remains conductive up to Ra = 103. With increase of Ra, the mode of heat transfer changes from conduction to convection. It has been observed that the average Nusselt number remains constant for Ra up to 103 and then starts changing when Ra is increased further. This led to the further detailed study about the flow behavior in a cavity with undulations. Because of the nature of the imposed boundary conditions, there are two large vortices formed. The left side vortex adjacent to the flat vertical wall always remains single cell and is unaffected by Ra, amplitude and number of undulations. For a single undulation, when Ra is increased to 106, the right side large vortex breaks into two cells for amplitude above a certain value (0.06) giving rise to first saddle point and right side second vortex center. For two and three undulation cases, in addition to these, a second saddle point and right side third vortex appear beyond some amplitude (0.07 and 0.03, respectively).
