Thermal analysis of buoyancy-driven flow in a square enclosure filled with porous medium

The scope of the present investigation is to explore the thermal convection in square-shaped, porous enclosures demonstrating the impact of cavity orientation. The differential equations controlling the fluid flow and energy transfer are solved using the finite volume framework. The Darcy-BrinkmanForchheimer model is selected for porous medium. The investigation is executed for modified Rayleigh number (Ra-m) from 10(2) to 10(4). The orientation of the enclosure is varied from the horizontal position (gamma = 0 degrees) to the vertical position (gamma = 90 degrees) at an interval of 15 degrees. The flow pattern and the heat transfer are examined using the traditional method of streamlines and isotherms. The Nusselt number (Nu(m)) is employed to measure the transport of energy by thermal convection. The results indicate that the Nu(m) varies with the change in the Ra-m and cavity orientation. When the cavity is rotated from the horizontal position to the vertical position, the thermal convection increases up to a critical inclination angle (gamma c). However, the heat transfer by convection declines beyond the critical inclination angles. It is noted that the critical inclination angle varies with the change in the Ra-m. The enhancement in energy transport by convection varies with Ra-m. The augmentation in thermal convection is measured by the heat transfer enhancement parameter (xi). The augmentation in energy transport is maximum for lower Ra-m = 10(2) (xi = 34.9 %) and minimum for higher Ram = 104 (xi = 24.3 %). This investigation helps in designing a thermal system that results in the optimum utilization of energy resources. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 4th International Conference on Advances in Mechanical Engineering and Nanotechnology.

Automated summary

The present investigation explores thermal convection in square-shaped, porous enclosures and its dependence on cavity orientation. The fluid flow and energy transfer equations are solved using the finite volume framework, and the Darcy-Brinkman-Forchheimer model is employed for porous medium. The study covers a range of modified Rayleigh numbers and examines the flow pattern, heat transfer, and energy transport by thermal convection. The results show that the Nusselt number varies with the modified Rayleigh number and cavity orientation, with an increase in convection up to a critical inclination angle and a decline thereafter.