Analysis of Filtration Efficiency in Numerical Simulations of Biofuels Combustion
Congress: ENCIT
ABSTRACT:
The climate crisis has been pushing human activities to undergo a decarbonization process in order to mitigate potential environmental catastrophes in the short and long term future. In this scenario, biofuels have gained promi- nence as a key strategy for decarbonization, especially in Brazil, as they provoke fewer carbon dioxide emissions in their combustion compared to fossil fuels. Furthermore, this potential for reducing emissions can be increased through the adoption of more efficient particulate filters in biofuel-powered machines, such as cars. Therefore, this study aims to investigate different geometries of porous channels of particulate filters and identify which geometric factors make these filters more efficient, contributing to a better understanding of the filtering phenomenon in this context. To accomplish this goal, a portion of these filters was represented in a bidimensional geometry and a matching unstructured mesh with three different types of solid obstacles distributions representing the porous aspect of the filters: aligned circular obstacles, misaligned circular obstacles and circular obstacles with randomized positions. Each simulation considered three vari- ations of obstacle radius, resulting in a total of nine simulations. All of the simulations were run on an in-house Python code developed specifically for this research, through the discretization of the stream function-vorticity formulation using the Finite Element Method. The important parameters analyzed in the current study were flow speed, vorticity and stream function. From the results obtained, it was observed that the size and distribution of circular obstacles, that represented the porous medium within the channel, are variables that influence the filtration efficiency of the filters. The simulations identified distinct trends in the way these parameters influence the filtration efficiency, and these trends were quantified using a filtration quality parameter introduced in this study. Ultimately, this research addresses the importance of opti- mizing particulate filter design for biofuel-powered systems and aims to contribute to this effort by offering insights into the relationship between the geometry of particulate filters and their efficiency.