title: Ultrafine particle emission characteristics of diesel engine by on-board and test bench measurement.
abstract: This study investigated the emission characteristics of ultrafine particles based on test bench and on-board measurements. The bench test results showed the ultrafine particle number concentration of the diesel engine to be in the range of (0.56-8.35) x 10(8) cm(-3). The on-board measurement results illustrated that the ultrafine particles were strongly correlated with changes in real-world driving cycles. The particle number concentration was down to 2.0 x 10(6) cm(-3) and 2.7 x 10(7) cm(-3) under decelerating and idling operations and as high as 5.0 x 10(8) cm(-3) under accelerating operation. It was also indicated that the particle number measured by the two methods increased with the growth of engine load at each engine speed in both cases. The particle number presented a "U" shaped distribution with changing speed at high engine load conditions, which implies that the particle number will reach its lowest level at medium engine speeds. The particle sizes of both measurements showed single mode distributions. The peak of particle size was located at about 50-80 nm in the accumulation mode particle range. Nucleation mode particles will significantly increase at low engine load operations like idling and decelerating caused by the high concentration of unburned organic compounds.
authors.affiliation: School of Automobile Studies, Tongji University, Shanghai 201804, China. huangc@saes.sh.cn
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.forename: Diming
authors.initials: D
authors.lastname: Lou
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Hu
authors.forename: Piqiang
authors.initials: P
authors.lastname: Tan
authors.forename: Di
authors.initials: D
authors.lastname: Yao
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Jin
authors.initials: J
authors.lastname: Ren
authors.forename: Changhong
authors.initials: C
authors.lastname: Chen
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions