Analysis on the Effect of Different Driving Conditions on Dispersion of Vehicle Exhaust Based on Fluent

To study the difference of the dispersion of vehicle exhaust (carbon monoxide, CO) under different driving conditions, namely, idling, constant speed, uniform acceleration, uniform deceleration, uniform acceleration followed by uniform deceleration and uniform deceleration followed by uniform acceleration, a numerical simulation was designed and performed by using a multipurpose commercial fluid dynamics software Fluent in this study. The relative deviations of CO concentration under different driving conditions were calculated and compared with treating the driving condition of constant velocity as benchmark. It was shown that the maximum relative deviation can be reached as high as 39 %, which demonstrates that the effect of driving conditions on the dispersion of vehicle exhaust cannot be neglected especially during the prediction of the concentration of the pollutant in the street canyon.