Opposing-buoyancy mixed convection through and around arrays of heated cylinders

Tang, Tingting1,2; Li, Zhiyong1,3; Yu, Shimin1,4; Li, Jianhui1; Yu, Peng1,2

2022-09-23

10.1017/jfm.2022.740

JOURNAL OF FLUID MECHANICS   影响因子和分区

0022-1120

1469-7645

We numerically investigated the opposing-buoyancy mixed convection through and around square arrays of 10 x 10 heated circular cylinders with the solid fraction (phi) ranging from 0.0079 to 0.66 and the Richardson number (Ri) varying from 0 to 1 at a fixed Reynolds number (Re) of 100. Our simulations revealed that the large mean recirculation in the far wake can be detached from or connected with the vortex pair in the near wake for different combinations of Ri and phi. Also, it was found that the array with relatively small phi can significantly promote flow instability even at moderate Ri. The instability, which is closely related to the fluctuating heat flux, develops from the lateral sides to the downstream side of the array and gives rise to the large mean recirculation in the far wake. The power spectra density of the array-scale force coefficients demonstrates that the flow undergoes different bifurcation behaviours under various parameter combinations, which reflects the interaction between the near-wake and far-wake vortexes. Interestingly, the Strouhal-Richardson number curves can be collapsed onto the same curve when Ri is increased by a phi-dependent factor. Also, for phi <= 0.22, both the mean drag coefficient and the mean Nusselt number of the array were found to decrease linearly with Ri since the buoyancy within the array becomes prominent in this range of phi.

convection in porous media buoyancy-driven instability

SCI

英语

第一 ; 通讯

NSFC["12172163","12002148","11672124"] ; Shenzhen Peacock Plan[KQTD2016022620054656] ; Guangdong Provincial Key Laboratory of Turbulence Research and Applications[2019B21203001]

Mechanics ; Physics

Mechanics ; Physics, Fluids & Plasmas

WOS:000859149400001

CAMBRIDGE UNIV PRESS

ENGINEERING

Web of Science

1.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China
2.Southern Univ Sci & Technol, Ctr Complex Flows & Soft Matter Res, Shenzhen 518055, Peoples R China
3.Dongguan Univ Technol, Dongguan 523808, Peoples R China
4.Harbin Inst Technol, Harbin 150001, Peoples R China

Tang, Tingting,Li, Zhiyong,Yu, Shimin,et al. Opposing-buoyancy mixed convection through and around arrays of heated cylinders[J]. JOURNAL OF FLUID MECHANICS,2022,949.

Tang, Tingting,Li, Zhiyong,Yu, Shimin,Li, Jianhui,&Yu, Peng.(2022).Opposing-buoyancy mixed convection through and around arrays of heated cylinders.JOURNAL OF FLUID MECHANICS,949.

Tang, Tingting,et al."Opposing-buoyancy mixed convection through and around arrays of heated cylinders".JOURNAL OF FLUID MECHANICS 949(2022).