Symmetric and asymmetric bifurcations of natural convection inside circular cavity in the route to chaos

Natural convection occurs when pipe floating at the water surface during night, which can be regarded as a circular cross-section enclosure heated from below and cooled from the top. Numerical investigation is carried out with focuses on the flow configurations in the route to chaos. When Ra is lower than 10 3 , convection is neglectable and conduction dominate the heat transfer. The flow becomes chaos and unsteady when Ra increases to 10 8 . In the route to chaos, the number of cell increase with the decrease of the cell size. It is found that a symmetric to asymmetric bifurcation of flow configuration followed by a asymmetric to symmetric exist for Ra between 10 3 to 10 6 .