Thermal pattern of nano-encapsulated PCM in a lid-driven cavity with presence of a heated body, magnetic field and limited permeability

Abstract

This study attempts to improve the thermal characteristics of nano-encapsulated phase change materials (NEPCMs) for heating and cooling applications. The PCM particles are added to water to improve the thermal performance by the latent heat of phase change. NEPCM is confined in a porous prism lid-driven cavity with a lower zigzag wall. The cavity contains an elliptic heated cylinder and is subjected to magnetic field. The study is modeled using the Galerkin finite element method to solve the governing equations. The influential parameters are highlighted, including the impacts of medium permeability (Darcy number (Da) = 10−2 – 10−5), the strength of the magnetic field (Hartmann number (Ha) = 0–100), the orientation of an elliptic heated body (θ = 0° – 135°), and the speed of the lid (Reynolds number (Re) = 1–500). For all studied cases, it was observed that the thermal performance is improved by increasing the Re and Da and decreasing Ha. Increasing Re from 0 to 500 and Da from 10−5 to 10−2 enhances Nu by 335% and 94.7%, respectively. While raising Ha from 0 to 100 and the inclination angle to 90° decreases Nu by 5.3% and 6.7%, respectively.