Mm. Maricq et al., Gasoline vehicle particle size distributions: Comparison of steady state, FTP, and US06 measurements, ENV SCI TEC, 33(12), 1999, pp. 2007-2015
Citations number
16
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Factors influencing the number and size of tailpipe particles from port inj
ection, spark ignition vehicles are examined by comparing emissions recorde
d during steady-state operation and those obtained from FTP and US06 drive
cycles. Size distributions are measured using the scanning mobility particl
e sizer (SMPS) and the electrical low-pressure impactor (ELPI). Steady-stat
e particulate emissions are examined as a function of vehicle speed and air
to fuel ratio. The emission rates increase moderately with increasing spee
d hut climb steeply with decreasing A/F. This is consistent with the observ
ations from transient drive cycle measurements where particulate emissions
occur predominantly during periods of heavy acceleration. As expected from
the more aggressive speed and acceleration of the US06 cycle, the per mile
particulate emission rates are higher than for phases 2 and 3 of the FTP. F
or the eight vehicles tested, the US06 mass emissions range from 1.2 to 9.6
mg/mi. Use of a US06-compliant calibration leads to a factor of 2 reductio
n of particulate emissions, in both number and mass, over the drive cycle.