Date of Graduation
Statler College of Engineering and Mineral Resources
Mechanical and Aerospace Engineering
PM has been shown to be harmful to people, animals, and the environment. For this reason PM is a regulated emission. As federal regulation of particulate matter (PM) becomes tighter, the need to accurately measure it becomes paramount. As the limit decreases, it becomes more difficult to measure PM due to the inaccuracies in the measurement equipment, and the nature of the particles to be lost in the sampling system.;This study investigated the error propagation and particle loss in two common PM mass measurement systems, the full flow sampling system, also called the constant volume sampling (CVS), and the partial flow sampling (PFS) systems. Computer models were created to simulate the propagation of inaccuracies in the components to total error, and to simulate how many and why particles get lost in the systems. The data that the models used came from transient testing of a 2004 model year heavy-duty diesel engine from which both a CVS and PFS system were used to measure the emissions of PM. Particle spectrometer data were also collected and used in the particle loss model. The models produced batch error results and integrated mass loss results. The models also produced continuous error propagation and continuous particle loss to give more insight as to when in the transient test the largest errors and particle losses were occurring. Another useful result from the particle loss model was showing which types of losses affect which size of particle. Four types of particle loss were considered: diffusion, thermophoretic, isokinetic, and bend. Each of the loss types affected the particle distribution differently.;The CVS system had less error in its measurement, but more particles were lost therein. The PFS system had much more error than the CVS, but fewer particles were lost. The relative error in the CVS system was minimal at approximately 10%, whereas the PFS system had a relative error of approximately 36%. The losses in the CVS system lowered the mass result by approximately 11%, and the losses in the PFS system lowered the mass result by approximately 5%.
Kimble, Nathan, "Model Based Evaluation of the Differences between Full and Partial Flow Particulate Matter Sampling Systems" (2011). Graduate Theses, Dissertations, and Problem Reports. 2256.