Abstract
The air pollution induced by urban traffic has addressed much attention in recent years as the rapid urbanization and the fast increase of vehicle number in urban area. In this study, we attempted to investigate the dispersion behavior of exhaust gas from exhaust pipe using computational fluid dynamics approach. The time-averaged CO2 concentration, velocity and temperature profiles along the centerline of the vehicular exhaust plume were simulated in varied situations. The computational results showed good agreement with the experimental data and the numerical model was validated to be an effective method to investigate the pollutant dispersion in the near-wake region of a vehicle. Based on it, the numerical simulations were extended to explore the impacts of the emit concentration, the emit direction and the incoming velocity on the flow dynamics and CO2 dispersion. The outputs indicated that the emit concentration could change the pollution level in the near-wake region of a vehicle and the emit direction may alter the spreading direction of the vehicular exhaust plume. The incoming velocity was found to have dominant influence on the dispersion of pollutant due to induced vortices and turbulence behind the vehicle. These findings are expected to provide important insight into evaluating the design and control strategies for alleviating mobile source emissions.
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References
Albriet B, Sartelet KN, Lacour S, Carissimo B, Seigneur C (2010) Modelling aerosol number distributions from a vehicle exhaust with an aerosol CFD model. Atmos Environ 44:1126–1137
Aliyu AS, Ramli AT, Saleh MA (2014) Environmental impact assessment of a new nuclear power plant (NPP) based on atmospheric dispersion modeling. Stochastic Environ Res Risk Assess 28:1897–1911
Blocken B, Tominaga Y, Stathopoulos T (2013) CFD simulation of micro-scale pollutant dispersion in the built environment. Build Environ 64:225–230
Boisvert JB, Deutsch CV (2011) Modeling locally varying anisotropy of CO2 emissions in the United States. Stoch Environ Res Risk Assess 25:1077–1084
Brugge D, Durant JL, Rioux C (2007) Near-highway pollutants in motor vehicle exhaust: review of epidemiologic evidence of cardiac and pulmonary health risks. Environ Health 6:23
Carpentieri M, Kumar P, Robins A (2011) An overview of experimental results and dispersion modeling of nanoparticles in the wake of moving vehicles. Environ Pollut 159:685–693
Dong G, Chan TL (2006) Large eddy simulation of flow structures and pollutant dispersion in the near-wake region of a light-duty diesel vehicle. Atmos Environ 40:1104–1116
Gérardin F, Gentric C, Midoux N (2014) Particle dispersion in the near-wake of an isolated rotating wheel: experimental and CFD study. J Aerosol Sci 76:56–71
Gosman AD (1999) Developments in CFD for industrial and environmental applications in wind engineering. Wind Eng Ind Aerodyn 81:21–39
Hathway EA, Noakes CJ, Sleigh PA, Fletcher LA (2011) CFD simulation of airborne pathogen transport due to human activities. Build Environ 46:2500–2511
HEI (2010) Traffic-related air pollution: a critical review of the literature on emissions, exposure, and health effects. Health Effects Institute, Boston, MA
Hoek G, Brunekreef B, Goldbohm S, Fischer P, van den Brandt PA (2002) Association between mortality and indicators of traffic-related air pollution in the Netherlands: a cohort study. Lancet 360:1203–1209
Huang H, Akutsu Y, Arai M, Tamura M (2000) A two-dimensional air quality model in an urban street canyon: evaluation and sensitivity analysis. Atmos Environ 34:689–698
Kalthoff N, Baumer D, Corsmeier U, Kohler M, Vogel B (2005) Vehicle-induced turbulence near a motorway. Atmos Environ 39:5737–5749
Kanda I, Uehara K, Yamao Y, Yoshikawa Y, Morikawab T (2006) A wind-tunnel study on exhaust gas dispersion from road vehicles-Part I: velocity and concentration fields behind single vehicles. J Wind Eng Ind Aerodyn 94:639–658
Kim JJ, Baik JJ (2003) Effects of inflow turbulence intensity on flow and pollutant dispersion in an urban street canyon. J Wind Eng Ind Aerodyn 91:309–329
Kim JJ, Baik JJ (2004) A numerical study of the effects of ambient wind direction on flow and dispersion in urban street canyons using the RNG k-ε turbulence model. Atmos Environ 38:3039–3048
Kunzli N, McConnell R, Bates D, Bastain T, Hricko A, Lurmann F, Avol E, Gilliland F, Peters J (2003) Breathless in Los Angeles: the exhausting search for clean air. Am J Public Health 93:1494–1499
Launder BE, Spalding DB (1974) The numerical computation of turbulent flows. Comput Methods Appl Mech Eng 3:269–289
Lee EWM (2009) Application of an intelligent model developed from experimental data to building design for fire safety. Stoch Environ Res Risk Assess 23:493–506
Liu CH, Barth MC (2002) Large-eddy simulation of flow and scalar transport in a modeled street canyon. J Appl Meteorol 41:660–673
Mohamed FY (2013) Numerical modeling on air quality in an urban environment with changes of the aspect ratio and wind direction. Environ Sci Pollut Res 20:3975–3988
Murakami S (1990) Numerical simulation of turbulent flow field around cubic model current status and applications of k-ε model and LES. Wind Eng Ind Aerodyn 33:139–152
Murakami S, Mochida A, Hayashi Y (1988) Modification of production terms in k-ε Model to remove overestimate of k value around windward corner. 10th Wind Engineering Symposium, 199–204
Sagrado APG, van Beeck J, Rambaud P, Olivari D (2002) Numerical and experimental modelling of pollutant dispersion in a street canyon. J Wind Eng Ind Aerodyn 90:321–339
Sahlodin AM, Sotudeh-Gharebagh R, Zhu YF (2007) Modeling of dispersion near roadways based on the vehicle-induced turbulence concept. Atmos Environ 41:92–102
Salim SM, Cheah SC, Chan A (2011) Numerical simulation of dispersion in urban street canyons with avenue-like tree plantings: comparison between RANS and LES. Build Environ 46:1735–1746
Sharma P, Khare M (2001) Modeling of vehicular exhausts–a review. Transp Res Part D 6:179–198
Tsai MY, Chen KS (2004) Measurements and three-dimensional modeling of air pollutant dispersion in an urban street canyon. Atmos Environ 38:5911–5924
Yang F, Kang YM, Gao YW, Zhong K (2015) Numerical simulations of the effect of outdoor pollutants on indoor air quality of buildings next to a street canyon. Build Environ 87:10–22
Zhan WJ, Zhang Y, Ma WC, Yu Q, Chen LM (2013) Estimating influences of urbanizations on meteorology and air quality of a Central Business District in Shanghai, China. Stoch Environ Res Risk Assess 27:353–365
Acknowledgments
The contents presented here are partially supported by the National Natural Science Foundation of China (11302125), Hong Kong RGC-GRF Grant (CityU 118212), Hong Kong CityU SRG Grant (7004360), and Natural Science Foundation of Guangxi (2012GXNSFBA053015 & 2014GXNSFAA118021).
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He, Hd., Shi, W. & Lu, WZ. Investigation of exhaust gas dispersion in the near-wake region of a light-duty vehicle. Stoch Environ Res Risk Assess 31, 775–783 (2017). https://doi.org/10.1007/s00477-016-1208-8
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DOI: https://doi.org/10.1007/s00477-016-1208-8