Numerical Simulation of the Natural Convective Heat Transfer of Nanofluids in a Square Cavity Based on Different Predictive Models for Single-Phase and Multiphase Flow Mixtures

Abstract

The flow and heat transfer characteristics of nanofluids in a square cavity were simulated using single-phase and mixed-phase flow models, and the simulation results were compared with the corresponding experimental values. The effects of different prediction models for the thermal properties of nanofluids, Grashof number, and volume fraction on the Nusselt number were analysed. The velocity and temperature distributions of the nanofluid and deionised water in the square cavity were compared, and the effects of the temperature and flow fields on the enhanced heat transfer were analysed according to the field synergy theory. The results show that for the numerical simulation of convective heat transfer in water, both the single-phase flow models and multi-phase flow mixing models had high prediction accuracy. For nanofluids, single-phase flow did not reflect the heat transfer characteristics well, and the simulation results of the single-phase flow model relied more strongly on a highly accurate prediction model for the physical parameters. The multi-phase flow mixing model could better reflect the natural convective heat transfer properties of the nanofluids in a the square cavity. The nanofluid could significantly improve the flow state in the square cavity, thereby facilitating enhanced convective heat transfer. When the concentration is 2% (Grashof number is 1×106), the average Nusselt number of the nanofluid is increased by 19.7% compared with the base fluid.

Nanofluid natural convection of hot concentric cylinder in oval-shaped porous cavity at different eccentricity

“…, 2023; Marafie, 2023; Thirumalaisamy and Reddy, 2023; Rana et al. , 2023; Dong et al. , 2023; Hosseinzadeh et al.…”

“…There are many scientific papers that were conducted and reviewed for different shapes of the porous cavity to study and investigate the nanofluid flow and natural heat transfer (Chandra and Bera, 2023;Venkatadri et al, 2023;Marafie, 2023;Thirumalaisamy and Reddy, 2023;Rana et al, 2023;Dong et al, 2023;Hosseinzadeh et al, 2021). investigated the free convection inside a square cavity, which consisted of two cases of an arrangement of two layers of porous and nanofluid.…”