Two-dimensional transient natural convection around a horizontal circular cylinder in a rectangular cavity

摘要

Two-dimensional transient natural convection of water around a horizontal cooled circular cylinder in a rectangular cavity was studied numerically. It was found that in the early stage of the evolution the flow is symmetric and the temperature field takes the form of a plume. After a while the flow begins to sway and then the stagnation points at the cylinder begin to move. The average Nusselt number decreases rapidly until the natural convection effect becomes dominant. The total kinetic energy increases rapidly after the beginning of cooling, reaches a maximum, and then begins to fluctuate.