Thermal convection subjected to perturbations from the bottom of a top open cavity

• Published in: Physics of fluids (1994) 2024-09, Vol.36 (9)
• Main Authors: Qiao, Manman, Jiang, Feng, Gao, Zhu, Xu, Mengfan, Yu, Tianchong, Li, Shiyang, Zhang, Hongsheng, Xu, Feng
• Format: Article
• Language: English
• Subjects: Convection heating; Free convection; Heat transfer; Periodic variations; Perturbation; Prandtl number; Scaling laws; Thermal simulation
• ISSN: 1070-6631; 1089-7666
• DOI: 10.1063/5.0223296

Perturbations are very common in the transition and heat transfer of thermal convection in nature and industry. Accordingly, thermal convection on a top-open cavity subjected to periodic and random perturbations is investigated using three-dimensional numerical simulation. A great number of numerical experiments are performed at various Rayleigh numbers and a fixed Prandtl number of 0.71 by introducing periodic and random numerical perturbations. Numerical results demonstrate that there exists the effect of periodic perturbations on the transition route over 3.5 × 103 ≤ Ra ≤ 8.5 × 104. That is, the transition route to chaos is sensitive to the amplitude of random perturbations for, e.g., 0.01 ≤ Ar ≤ 0.05, which is also characterized. Furthermore, heat transfer enhancement under periodic and random perturbations is quantified with the scaling law. This study sheds new light on the influence of periodic and random perturbations on thermal convection on the top-open cavity below heating. The possibility to control heat transfer is revealed by introducing random perturbations on the bottom of the top-open cavity.