Electro-magnetic Enhanced Mixed-convection of a Confined Slot NEPCM-water Impinging Jet Equipped with Metal Foam

This study tackles a complicated heat transfer problem about the cooling capability of a confined slot NEPCM-water suspension impinging jet for cooling a hot surface within the mixed convective region (with Ri = 1 and Re = 100 and 300). A NEPCM-water slurry comprises nano-sized capsules containing phase change material particles dispersed in a water-based solution. The cooling medium involves a porous metal foam (Da = 0.001), and the entire configuration is subjected to a uniform magnetic field that satisfies the laminar region (Ha = 50, λ = -75°) and electric field (between the surface and confining wall). The non-dimensional governing equations of both the fluid and electromagnetic field are solved by ANSYS Fluent. This involves implementing a nondimensionalization scheme and incorporating additional partial differential equations (PDEs) into the code. Additionally, memory allocation is optimized for efficient execution. Flow patterns, isotherms, heat capacity ratio, entropy generation components, and Bejan number are computed for both water and a 2% NEPCM-water suspension. The findings indicate that increasing the Reynolds number from 100 to 300, coupled with the introduction of electromagnetic fields (EMF) enhances Nuave by 67.1% for the NEPCM-water slurry. However, this increase in heat transfer is accompanied by a proportional rise in entropy generation under EMF at Re = 300. Interestingly, the simultaneous application of electric and magnetic fields results in a notable reduction in entropy generation, with Ngen decreasing by 35% and 14% for the NEPCM-water suspension at Re = 100 and 300, respectively, compared to pure water. Moreover, the average Bejan number (Beave) exhibits a decreasing trend with increasing Reynolds numbers, indicating a diminishing relative importance of heat transfer irreversibility. By the introduction of EMF, Beave demonstrates a 35.9% decline for NEPCM suspension at Da = 0.001 as Re increases from 100 to 300. These results underscore the complex interplay among fluid dynamics, electromagnetic fields, and entropy generation in impinging jet systems, offering effective understandings for improving heat transfer methods across many industrial applications.