Date of Award

6-2022

Document Type

Restricted (Opt-Out)

Degree Name

Bachelor of Science

Department

Mechanical Engineering

First Advisor

Ann Anderson

Keywords

Catalytic converters, Aerogels, Catalytic aerogels, Lattice Boltzmann Method, Diffusion Limited Cluster Aggregation Method, Computational fluid dynamics

Abstract

Catalytic converters are critical devices in automotive vehicles; they convert the toxic exhaust from internal combustion engines into less harmful byproducts. In a catalytic converter, catalytic particles line a porous substrate and react with the automotive exhaust as it flows through the structure. Precious metals such as rhodium, palladium, and platinum are used as the catalytic particles. The high price of these metals and the difficulties in mining them introduce challenges for manufacturing catalytic converters. Aerogels are highly porous materials which could be used in catalytic converters to lower these costs. Theoretically, this high porosity should allow for more surface area on which catalytic reactions can occur and thus increase the effectiveness of the catalytic converter, which could allow for the use of less expensive catalytic particles. Experimental research has shown the promise of using aerogels in catalytic converters, and there is a need for computational modeling to optimize the aerogel structure.

In this research, a two-dimensional computational model was developed for flow through aerogel materials to study the impact of the aerogel properties and the catalyst loading on the overall catalytic potential. The D2Q9 Lattice Boltzmann (LB) method was implemented for the fluid flow model and was used to track the number of fluid and catalyst particle collisions. The Diffusion Limited Cluster Aggregation (DLCA) method was used to create computational models of aerogel structures, with control over the structures’ density and porosity. A pore size distribution calculator was implemented to measure the resulting DLCA pore sizes. A catalytic particle distribution algorithm was implemented which randomly distributed the catalyst throughout the aerogel model. The percentage of catalyst to potential catalytic sites and the catalytic particle diameter were controlled. Results demonstrate that the LB method and the DLCA method can be used together to measure the number of fluid-catalyst interactions in the simulated catalytic aerogel. Future research will continue the development of this model so that it can be used to calculate the overall catalytic potential and optimize the aerogel structure.

Download

Campus Access Only, please contact for assistance.

Share

COinS
 

Rights Statement

In Copyright - Educational Use Permitted.