Natural Convection in Enclosed Porous or Fluid Media
In Saatdjian, E., Lesage, F., and Mota, J.P.B, “Transport Phenomena Projects: A Method to Learn and to Innovate, Natural Convection Between Porous, Horizontal Cylinders,” Chemical Engineering Education, 47(1), 59-64, (2013), the numerical solution of natural convection between two porous, concentric, impermeable cylinders was discussed. This problem is concerned with the insulation of horizontal pipes. It was given as a project to senior/graduate students in the advanced transport phenomena course where CFD is taught. In this paper, we discuss a related problem. Instead of placing over the hot cylinder the thermal insulation in a concentric position, the same amount of insulation is placed eccentrically with the thinnest part of the insulating material at the top. The reason for this positioning is to suppress the formation of an additional recirculation cell at the top of the layer at high Rayleigh numbers. This new project is of the same level of difficulty as the previous one. Finally, other tube geometries and fluid layers are discussed. All of these projects have been given over the years to senior/graduate students in the CFD course we teach. The instructor can thus select from a wide variety of problems to set up a different CFD project every semester.