Research Article
Analysis of the Coupled Effects of Thermal Conductivity, Emissivity, and Rayleigh Number on the Thermal Behavior of a Porous Cavity
Souleye Faye*,
Fallou Sarr,
Lamine Arfang Sarr,
Omar Ngor Thiam,
Vincent Sambou
Issue:
Volume 11, Issue 1, February 2026
Pages:
1-14
Received:
16 December 2025
Accepted:
30 December 2025
Published:
29 January 2026
Abstract: This study presents a numerical investigation of coupled heat transfer in a partitioned two-dimensional cavity containing two porous zones interacting with the main fluid region. The Darcy–Forchheimer–Brinkman model is used to describe the momentum transport and fluid–porous medium interactions by accounting for viscous diffusion, permeability resistance, and inertial effects inside the porous layers, while the thermal behavior is governed by the combined effects of conduction, natural convection, and surface radiation. The numerical results show that the introduction of porous media significantly weakens buoyancy-driven flow, leading to attenuated circulation cells, straighter and more parallel isotherms, and a clear reduction in the convective Nusselt number along the heated walls. It is also demonstrated that increasing the effective thermal conductivity of the porous medium enhances heat conduction through the solid matrix and modifies the overall flow structure by redistributing the temperature gradients between the fluid and the porous zones. The Rayleigh number is identified as the primary parameter controlling the transition between conduction-dominated and convection-dominated regimes, with low values corresponding to diffusion-controlled heat transfer and higher values promoting stronger convection even in the presence of porous obstacles. In addition, radiative heat transfer is found to be mainly governed by wall emissivity and the thermal properties of the cavity boundaries, and higher emissivity markedly increases the radiative contribution to the total Nusselt number by reinforcing surface-to-surface thermal exchanges, which partially compensates for the attenuation of convection induced by the porous layers. These findings provide valuable physical insight and practical guidelines for the thermal design and optimization of passive systems incorporating porous materials such as solar distillers, thermal insulation components, and energy storage devices operating under combined heat transfer modes.
Abstract: This study presents a numerical investigation of coupled heat transfer in a partitioned two-dimensional cavity containing two porous zones interacting with the main fluid region. The Darcy–Forchheimer–Brinkman model is used to describe the momentum transport and fluid–porous medium interactions by accounting for viscous diffusion, permeability resi...
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Research Article
Environmental Impact Assessment and Spatial Distribution Analysis of Ternary Lithium-ion Battery Recycling in China Based on SimaPro
Yuan Jun
,
Li Long*
Issue:
Volume 11, Issue 1, February 2026
Pages:
15-24
Received:
16 March 2026
Accepted:
8 April 2026
Published:
21 April 2026
DOI:
10.11648/j.ijees.20261101.12
Downloads:
Views:
Abstract: With the rapid growth in the number of new energy pure electric vehicles, China is about to enter a phase of concentrated retirement of power batteries. The recycling and treatment of retired batteries will have significant environmental impacts and exhibit spatial heterogeneity. Existing research primarily focuses on national aggregate levels, lacking integrated analysis of the “spatiotemporal distribution of retired batteries—environmental impacts of recycling processes—regional environmental impact variations.” This study forecasts the retirement volume of ternary lithium batteries across China's 31 provinces (autonomous regions and municipalities) from 2025 to 2031 based on pure electric vehicle ownership, integrating this with life cycle assessment (LCA). Within SimPro, an inventory model was established using “combined thermal-wet recycling of 1 kg of end-of-life ternary lithium battery cells” as the functional unit. The ReCiPe2016 Midpoint methodology was employed to quantify indicators, including global warming potential (GWP), human toxicity (HT), eutrophication potential (EP), acidification potential (AP), and ozone depletion potential (ODP). The unit impacts were further scaled to regional levels to derive the environmental impact potential at the regional level during the wave of battery retirement. Results indicate significant provincial variations in retired ternary lithium batteries and their environmental impact potential. Provinces with substantial environmental impacts are primarily concentrated in regions with high new energy vehicle penetration and dense economic activity. By 2025, Beijing and Guangdong should prioritize optimizing battery recycling technologies. By 2031, a trend toward expansion into Central China emerges, with impacts concentrated in Central, East, South, and North China, where the highest carbon emissions could reach 12 million tons. Guangdong and Jiangsu will replace Beijing as the highest carbon emitters, while Qinghai will replace Tibet as one of the lowest emitters. Process contribution analysis indicates that energy consumption and key chemical inputs during the wet processing stage dominate multiple indicators. This research provides quantitative evidence for prioritizing recycling zone planning and process optimization.
Abstract: With the rapid growth in the number of new energy pure electric vehicles, China is about to enter a phase of concentrated retirement of power batteries. The recycling and treatment of retired batteries will have significant environmental impacts and exhibit spatial heterogeneity. Existing research primarily focuses on national aggregate levels, lac...
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