Thermal management and natural convection flow of nano encapsulated phase change material (NEPCM)-water suspension in a reverse T-shaped porous cavity enshrining two hot corrugated baffles: A boost to renewable energy storage

Abstract

Renewable energy systems may be turning to be more effectual and inexpensive and contributing lion's share of whole energy utilization in today's power hungry planet. The efficacious usage of solar energy needs a storage appliance which could simplify the storage of surplus energy, and finally provide such energy when it desires. One of the efficacious approach of storing thermic energy of higher density from renewable source is executed in a varying range of temperature positions by phase change materials (PCMs) or nano encapsulated phase change material (NEPCM) as their significant role in air-conditioning systems, thermal energy storage, computer chipsets, and thermal management of buildings. In view of this, the present investigations aims at natural convection flow, heat transfer, and entropy of NEPCM-water suspension in a reverse T-shaped porous cavity enshrining two hot corrugated baffles. The thermal control within the cavity is maintained by hot corrugated baffles, cooling of bottom and upper walls and managing the side walls as adiabatic. The governing equations are well established and converted into dimensionless structure and then solved subsequently by Finite Element method (FEM). Simulated outcomes might well be validated accurately and the influence of Rayleigh number (104≤Ra≤106), porosity (0.4≤ε≤0.8), Darcy number (10−4≤Da≤10−2), NEPCM particle volume fraction (0≤φ≤5%), length of the corrugated walls (0.10L≤b≤0.20L), and fusion temperature (0.2≤θf≤0.8) on the heat transfer features, isotherms, heat capacity ratio and streamlines is explored efficaciously. The outcomes of this study are that amplifying Raleigh number leads to the intensification of streamlines, velocity fields and structural change of phase change zone while decaying of Darcy number exhibits the opposite effect. Strengthening porosity of porous medium intensifies the streamlines, horizontal and vertical velocity. Growth of the length of baffles yields emaciation of streamlines, flow fields, and enormous rate of heat transfer. Heat capacity ratio attains a constant value 0.97 outside melting-solidification zones within the cavity. Rise in the fusion temperature results in the expansion and shifting of melting-solidification zone. When φ rises from 1% to 2%, Nuave uplifts and yields its minimum enhancement while with rise of φ from 1% to 5%, Nuave upgrades and yields its maximum enhancement at fixed Darcy and Raleigh numbers.