Performance evaluation of metal foams in an asymmetrical heated channel

This investigation focuses on the thermal-hydraulic characteristics of aluminum metal foams with varying pore densities in horizontally oriented channel subjected to asymmetric heating by numerical computations. The objective of the study is to find the optimum pore density of the metal foam which gives higher thermo hydraulic performance in an asymmetrical heating channel. Hence, the novelty of the work is to find best among four various pore densities of the metal foam in an asymmetric heating horizontally oriented channel. The computational domain consists of a horizontal channel embedded with aluminum metal foams exhibiting distinct pore densities: 10 PPI (porosity = 0.95), 20 PPI (porosity = 0.90), 30 PPI (porosity = 0.92), and 45 PPI (porosity = 0.90). The heat source is modeled as an aluminum plate placed on the upper wall of the channel with constant heat flux and dissipates thermal energy through water flowing within the channel. The flow velocities at the channel inlet range from 0.02 m/s to 0.3 m/s. Flow dynamics are simulated using the Darcy-Extended Forchheimer (DEF) model, while thermal performance is evaluated based on the Local Thermal Equilibrium (LTE) assumption to account for heat transfer between the fluid and porous medium. The numerical simulations are benchmarked against experimental data reported in the literature for validation. From numerical results, it is observed that the 10 PPI foam performs 0.83, 0.54, and 3.65 times lesser pressure loss compared to 20, 30, and 45 PPI foams respectively. Among the investigated configurations, the aluminum foam with a pore density of 20 PPI demonstrates superior thermal-hydraulic performance, achieving only 2.57 % lesser enhancement in heat transfer efficiency and a 65 % reduction in pressure drop relative to the 45 PPI foam. This study provides a comprehensive examination of the interplay between pore density, flow dynamics, and thermal transport, establishing the 20 PPI foam as the optimal choice for the specified operating conditions.