Reduction in Motorcyclist Pollutant Exposure Intensity via the Aid of a Porous Front Fender and Rear Vent

Scooters are the most common form of transport for commuters in Taiwan, and their emissions account for the majority of the airborne pollutants present in metropolitan areas. These pollutants have a serious adverse effect on the health of motorcyclists and their passengers, and thus effective methods are required for minimizing the pollutant exposure intensity. Accordingly, the present study performs numerical simulations to investigate the pollutant dispersion efficiency of four different front fender and vent designs, namely (1) no fender spoiler and vents on two sides of scooter frame; (2) a fender spoiler and vents on two sides of scooter frame; (3) no fender spoiler and vents beneath scooter frame; and (4) a fender spoiler and vents beneath scooter frame. For each design configuration, the simulations consider two different fender porosity ratios, namely 50% and 70%. In addition, the effectiveness of a rear-mounted exhaust suppressor and various saddle designs in reducing the exhaust exposure concentration is also briefly examined. Overall, the simulation results show that, compared to a conventional fender/vent design (i.e., zero fender porosity, no fender spoiler, and no vents), the use of a fender with a porosity ratio of 70% and two vents beneath the scooter frame reduces the exhaust exposure concentration by 36% given no fender spoiler and 43% given the use of a fender spoiler. Furthermore, it is shown that the addition of an exhaust suppressor to the rear of the saddle or the use of a wide saddle width also achieves a moderate improvement in the pollutant dispersion efficiency.