An Integrated Laboratory and Axisymmetric Numerical Study of Convection in a Rotating Annulus with Bi-directional Thermal Forcings
摘要
This study combines laboratory experiments and 2D axisymmetric simulations to explore convection in a rotating cylindrical annulus with localized spot heating and uniform cooling. The effects of Taylor ( \(\textit{Ta}\) ) and Rayleigh ( \(\textit{Ra}\) ) numbers on flow dynamics and heat transport were investigated under constant heat flux and constant temperature conditions, with \(\textit{Pr} = 7\) . Experiments covered \(\textit{Ta} = 8.8 \times 10^7\) to \(2.7 \times 10^9\) and \(\textit{Ra} = 2 \times 10^8\) to \(1 \times 10^9\) , while simulations extended to \(\textit{Ta} = 2 \times 10^7\) and \(\textit{Ra} = 2.4 \times 10^7\) . Convection is confined to boundary layers, with diffusion dominating the interior flow. At \(\textit{Ta} = 0\) , isotherms are horizontal, while rotation spreads them due to quasi-hydrostatic and geostrophic balances. At low-to-moderate \(\textit{Ta}\) , baroclinic waves enhance heat transfer, peaking at an optimal \(\textit{Ta}_{\text {max}}\) . Beyond this, waves break into eddies, reducing \(\textit{Nu}\) . At very high \(\textit{Ta}\) , steady large-scale circulation dominates, making \(\textit{Nu}(\infty) \approx \textit{Nu}(0)\) . High heat fluxes result in significant temperature variations near the heating plate, even at lower rotations. These results underscore the complex interplay of rotation, thermal forcing, and heat transport.