In this study, a numerical investigation of mixed convective heat transfer in a square enclosure partitioned in two layers with a rotating circular cylinder at the middle of the cavity has been carried out. The experiments are performed with Al₂O₃–water nanofluid (upper layer) and superposed porous medium (lower layer). The upper and lower horizontal walls are assumed to be insulated, while the left and right walls are kept at high and low temperature respectively. Galerkin finite element method has been used to solve the dimensionless governing equations. This study is focused to investigate the effect of Darcy number (10⁻²≤ Da ≤10⁻⁵), Rayleigh number (10³≤ Ra≤10⁶), dimensionless angular rotational velocity (−6000≤ W ≤ 6000), solid volume fraction (0≤ ɸ ≤0.06), and the radius of the inner circular cylinder (R = 0.1, 0.2 and 0.3) on the heat transfer, fluid flow, and the physical characteristics thermal of the thermal fields. The results show that the intensity of the flow, steep temperature gradient, and the average Nusselt number (Nu) increase with increasing the value of Darcy number, Rayleigh number, and solid volume fractions at any cylinder radius. Moreover, the recirculation and isotherm distribution lines of the fluid at low Darcy numbers are high when the cylinder rotates counter-clockwise compering with clockwise. The findings also revealed that when W = 0, the maximum Nu is at R = 0.1 and decreases as the cylinder radius increases. Moreover, at high Darcy number, the highest local Nusselt number is found at the porous layer region in case of clockwise rotation while at the nanofluid layer region in case of anti-clockwise rotation.

在这项研究中，已经进行了对流换热的数值研究，该混合对流在腔体中间被旋转的圆柱体分隔成两层的方形外壳中进行了。实验是使用Al ₂ O _{3 –}水纳米流体（上层）和叠置的多孔介质（下层）进行的。假定上，下水平壁是隔热的，而左，右壁分别保持在高温和低温下。Galerkin有限元方法已用于求解无量纲的控制方程。这项研究的重点是研究的达西数（10的效果^-2 ≤沓≤10 ^-5），瑞利数（10 ³ ≤太阳神≤10 ⁶），无量纲的角旋转速度（-6000≤ W¯¯  ≤6000），固相体积分数（0≤ ɸ ≤0.06），并且内圆筒的半径（- [R 在传热= 0.1，0.2和0.3） ，流体流动以及热场的物理特性。结果表明，流动强度，陡峭的温度梯度和平均努塞尔数（Nu）随着在任何圆柱半径处的达西数，瑞利数和固体体积分数的值增加而增加。此外，当气缸逆时针旋转并顺时针旋转时，低达西数的流体的再循环和等温线分布较高。研究结果还表明，当W = 0时，最大Nu在R = 0.1处，并且随着圆柱半径的增加而减小。此外，在高达西数下，在顺时针旋转的情况下在多孔层区域发现最高的局部努塞尔数，而在逆时针旋转的情况下在纳米流体层区域发现最高的局部努塞尔数。