Stochastic 3D Carbon Cloth GDL Reconstruction and Transport Prediction

This paper presents the 3D carbon cloth gas diffusion layer (GDL) to predict transport behaviors of anisotropic structure properties. A statistical characterization and stochastic reconstruction method is established to construct the 3D micro-structure using the data from the true materials. Statistics of the many microstructure characteristics, such as porosity, pore size distribution, and shape of the void, are all quantified by image-based characterization. Furthermore, the stochastic reconstruction algorithm is proposed to generate random and anisotropic 3D microstructure models. The proposed method is demonstrated by some classical simulation prediction and to give the evaluation of the transport properties. Various reconstructed GDLs are also generated to demonstrate the capability of the proposed method. In the end, the adapted structure properties are offered to optimize the carbon cloth GDLs.

A finite element method for environmental and pollutant transport prediction

In the last decades, significant researches were dedicated to model the water-quality trends, soil erosion and material losses, contaminant transport, and their ecological impacts. The present paper investigates theoretically and presents a numerical model with finite elements of the pollutant transport and diffusion in 2-D environmental flow. It is a general model based on the physical groundwater flow equations presented into a new approach, in quantity structure. The mathematical model is based on mass conservation, including the main flow of the fluid and existing pollutants. The fluid mass conservation includes the changes in the groundwater volume flow in a selected time interval and the appeared modifications in the aquifer characteristics due to the pollutant presence are used in the numerical model. Some supplementary considerations concerning mathematical modeling are briefly presented. This model can be used to simulate the groundwater behavior in different situations, with a concentrated source of the pollutant, or with 2 sources of pollution. In the present paper are simulated only the aquifers with mainly horizontal groundwater flow and with a relatively known aquifer’s structure. The model is tested for a landfill near the Dambovita River, to predict the groundwater contamination and the time variation of concentration. Finally, some conclusions and references are presented.