Convection flow of nano-encapsulated phase change material in wavy chamber with double sliding walls, flame-shaped heating source, and magnetic force

This article aims to improve the convection flow within a two-dimensional chamber by utilizing nano-encapsulated phase change material (NEPCM). The chamber center contains a flame-shaped heating source, and the bottom wall is wavy. Forced convection occurs due to the motion of the chamber's side walls, while natural convection arises from the thermal gradient across the side walls. The Galerkin-finite element (GFEM) approach was employed to analyze the system's governing equations. The study investigates the impact of the following factors on heat transfer: wall velocity (Re = 10–1000), wall movement directions (both walls moving in a positive direction, both walls moving in a negative direction, and one wall negative and the other positive), intensity of the magnetic field (Ha = 0–100), and cavity porosity (Da = 10⁻⁵ – 10⁻²). The results demonstrate that increasing Re and Da improves the average Nusselt number (Nu_Avg). Conversely, raising the intensity of the magnetic field and moving the side walls in the opposite direction reduces Nu_Avg. At Re = 1000, increasing Da (10⁻² instead of 10⁻⁵) leads to a 139% increase in Nu_Avg, and decreasing Ha and moving walls in the same directions increase Nu_Avg by 11.5% and 640%, respectively.