Mixed convection flows from a revolving cylindrical cavity

Abstract

Efforts are made to describe the thermofluidic behavior around a spinning hot cylindrical open cavity with negligible wall thickness suspended in air within the laminar regime. Several important input parameters, such as, Rayleigh number $\left({10}^2\le \mathit{\text{Ra}}\le {10}^6\right),$ aspect ratio $\left(0.5\le H/D\le 10\right),$ and Reynolds number $\left(0\le {\mathit{\text{Re}}}_D\le 300\right)$ are considered to carry out the ongoing numerical analysis. Firstly, thermal plumes are provided to describe the pattern of flow and heat transfer around the heated surfaces of shell by considering the effect of $\mathit{\text{Ra}},$ $H/D,$ and ${\mathit{\text{Re}}}_D.$ It is predicted that the heated plume is thrown radially due to the presence of swirling motion $\left({\mathit{\text{Re}}}_D\ne 0\right)$ of the cylindrical shell unlike the pattern of thermal plume around the stationary vessel. Furthermore, the influence of ${\mathit{\text{Re}}}_D$ on behavior of cooling rate from inner $\left(Q_{\mathit{\text{iw}}}\right)$ and outer $\left(Q_{\mathit{\text{ow}}}\right)$ surfaces has also been predicted by considering both stationary and swirling conditions. A substantial growth in $Q_{\mathit{\text{iw}}}$ is noticed with the growth of ${\mathit{\text{Re}}}_D$ for a constant $H/D.$ This effect is substantially greater at lower $H/D$ compared to higher $H/D.$ Again, attempts are made to elucidate the influence of ${\mathit{\text{Re}}}_D$ on Nusselt number for cylindrical inner wall $\left({\mathit{\text{Nu}}}_{\mathit{\text{cyl}}-\mathit{\text{iw}}}\right),$ cylindrical outer wall $\left({\mathit{\text{Nu}}}_{\mathit{\text{cyl}}-\mathit{\text{ow}}}\right),$ base inner wall $\left({\mathit{\text{Nu}}}_{\mathit{\text{base}}-\mathit{\text{iw}}}\right),$ and base outer wall $\left({\mathit{\text{Nu}}}_{\mathit{\text{base}}-\mathit{\text{ow}}}\right).$ Fluid flow behavior around the stationary and revolving cylindrical open cavity is also explained by employing velocity vectors. Finally, an appropriate correlation demonstrating a reasonable agreement with numerical data is found for average Nusselt number in terms of $\mathit{\text{Ra}},$ $H/D,$ and ${\mathit{\text{Re}}}_D.$

Keywords:

• Cylindrical shell
• mixed convection
• spinning cavity
• thermal plume
• thermofluidic
• flow plume

Disclosure statement

The authors have no conflicts of interest to disclose.