Chaotic Behavior of Natural Convection in a Tall Rectangular Cavity with Non‐Isothermal Walls

A computational model is presented that extends prior work on unsteady natural convection in a tall rectangular cavity with aspect ratio 10. The solution to the weakly compressible Navier‐Stokes equation is computed for a range of Rayleigh numbers between $2⋅107$ and $2.2⋅108$ with Prandtl number 0.71. A detailed spectral analysis has been performed, which shows dynamic system behavior beyond the Hopf bifurcation that was not previously observed. The wider Rayleigh range reveals new dynamic system behavior for the rectangular geometry, specifically a return to a stable oscillatory behavior that was not predicted in prior work.