Evaluation of Transient Performance of Diesel Particulate Filters via Light Extinction and Scattering methods

The performance of diesel particulate filters (DPF) was assessed by means of the light extinction and scattering methods using three common-rail turbo-charged DI diesel engines. The temporal soot mass concentrations measured by the extinction method before and after DPF showed filtration efficiency over 90% under steady conditions, while it fluctuated widely under transient modes due to the temporal delay in filtration process. The soot aggregate size measured by the Rayleigh-Debye scattering approach ranged from 80 nm to 140 nm depending on the engine operating conditions, and showed little change while particles were filtrated in DPF. Simultaneous measurements of mass concentration and radius of gyration of soot aggregates under JE05 transient mode were successfully performed using a 4 liter common-rail diesel engine.