AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Evaluation of Self-pollution Inside School Buses Using a CFD and Multi-zone Coupled Model
Fei Li, EON LEE, Junjie Liu, Yifang Zhu, University of California, Los Angeles
Abstract Number: 232 Working Group: Indoor Aerosols
Abstract The in-cabin environment of a school bus is important for children’s health. The pollutants from its own exhaust can penetrate into the school bus cabin and increase children’s overall exposure to air pollutants. In this study, we adapted a coupled model, originally developed for building environment, to determine the relative contribution of the bus own exhaust to the in-cabin pollutant concentrations. The coupled model uses CFD (computational fluent dynamics) model to simulate for concentration outside the school bus and CONTAM (a multi-zone model) for the inside. The model was validated with experimental data in the literature. Using the validated model, we analyzed the effects of vehicle speed and tailpipe location on self-pollution inside the bus cabin. We confirmed that the pollution released from the tailpipe can penetrate into the bus cabin through gaps in the back emergency door. We found the pollutant concentration inside school buses was the highest when buses were driven at a medium speed. In addition, locating the tailpipe on the side, behind the rear axle resulted in less self-pollution since there is less time for the suction effect to take place. The developed theoretical framework can be generalized to study other types of buses. These findings can be used in developing policy recommendations for reducing human exposure to air pollution inside buses.