Abstract
Particulate matter (PM) poses significant risks to human health and the environment, making accurate measurement essential for exposure assessment and regulatory decisions. While traditional reference methods provide reliable data, they are often bulky, expensive, and difficult to maintain. Optical Particle Counters (OPCs) offer a cost-effective alternative, commonly used in clean rooms, residential spaces, and personal exposure monitoring. These devices rely on light scattering to measure PM concentrations. However, low cost OPCs face challenges related to calibration and measurement accuracy, requiring careful performance evaluation. This study used computational fluid dynamics (CFD) tools, CONVERGE Studio and ANSYS Fluent, to simulate a simplified OPC geometry and a commercial OPC. The simulations showed regional concentration variations influenced by flow dynamics and device geometry. In the CONVERGE simulation, each detection region exhibited an average percentage deviation of up to 32%, whereas Fluent showed a deviation of up to 10% for a concentration of 35 μg/m³. When the particle size was reduced along with a lower concentration of 10 μg/m³, the average regional deviation decreased to 6% for Fluent, suggesting that smaller particles more effectively followed the flow stream, resulting in lower variability. Furthermore, for the simulation of Alphasense OPC, the average percentage deviation of the regional concentration from the inlet was 19% for the velocity inlet boundary condition and 11% for the pressure inlet boundary condition, highlighting the impact of boundary conditions on concentration distribution. The application of two CFD packages for the simple chamber simulations showed regional concentration variations in the geometry. The results indicate that it is essential to consider regional concentration analysis in the design of commercial OPCs, to guide the choice of a region for detector placement.
Degree
MS
College and Department
Ira A. Fulton College of Engineering; Chemical Engineering
Rights
https://lib.byu.edu/about/copyright/
BYU ScholarsArchive Citation
Quarshie, Livingstone, "Assessing the Impact of Internal Flow Dynamics on Detection Region Concentrations of Low-Cost Optical Particle Counters" (2025). Theses and Dissertations. 10796.
https://scholarsarchive.byu.edu/etd/10796
Date Submitted
2025-04-24
Document Type
Thesis
Handle
http://hdl.lib.byu.edu/1877/etd13600
Keywords
Particulate matter, Optical Particle Counters, Detection Factor, Computational Fluid Dynamics, Rosin-Rammler Distribution
Language
english