Analysis of the bifurcating orbits on the route to chaos in confined thermal convection

Bifurcating thermal convection flows arising from a horizontal cylinder centred in a square-sectioned enclosure are studied numerically, with the aim of achieving a more detailed description of the sequence of transitions leading to the onset of chaos, and obtaining a more precise estimate of the critical values of the main system parameter, the Rayleigh number Ra. Only a value of the geometric aspect ratio A of the system is considered, namely A = 2:5, for which a period-doubling cascade was previously observed. Results give evidence of new and interesting features in the route to chaos, such as a window of quasiperiodic flow and the detection of high-order period orbits.