Experimental investigation of the effect of inlet particle properties on the capture efficiency in an exhaust particulate filter. (November 2017)

• Record Type: Journal Article
• Authors: Viswanathan, Sandeep; Rothamer, David; Zelenyuk, Alla; Stewart, Mark; Bell, David
• Is Part Of: Journal of aerosol science. Volume 113(2017)
• Page Start: 250
• Page End: 264
• Publication Date: 2017-11
• Subjects: APM Aerosol particle mass analyzer -- CAD Crank angle degrees -- CPC Condensation particle counter -- CPMA Centrifugal particle mass analyzer -- CT Computerized tomography -- DMA Differential mobility analyzer -- DSF Dynamic shape factor -- EEPS Engine exhaust particle spectrometer -- EFA Exhaust filtration analysis system -- EOI End of injection timing -- EPA Environmental protection agency -- FE Filtration efficiency (%) -- FV Filtration velocity (cm/s) -- FWHM Full-width at half-maximum -- GCI Gasoline compression ignition -- HL Heavy load engine operation -- IPSD Integrated particle size distribution method -- MBT Maximum brake torque -- MPPS Most penetrating particle size (nm) -- PFD Partial flow diluter -- PM Particulate matter -- PSD Particle size distribution -- SIDI Spark-ignited direct-injection -- SMPS Scanning mobility particle spectrometer -- SPLAT Single-particle laser-ablation time-of-flight mass spectrometer; Particulate matter (PM) -- Soot agglomerates -- Particle shape factor -- Gasoline particulate filter (GPF) -- Integrated particle size distribution (IPSD) method -- Spark ignition direct injection (SIDI) engine -- Gasoline direct injection (GDI) engine; Aerosols -- Periodicals; Aerosols -- Periodicals; Aérosols -- Périodiques; 541.34515
• DOI: 10.1016/j.jaerosci.2017.08.002
• Languages: English
• ISSNs: 0021-8502

Abstract

Abstract: The impact of inlet particle properties on the filtration performance of clean and particulate matter (PM) laden cordierite filter samples was evaluated using PM generated by a spark-ignition direct-injection (SIDI) engine fuelled with tier II EEE certification gasoline. Prior to the filtration experiments, an advanced aerosol characterization system that comprised of a scanning mobility particle spectrometer (SMPS), centrifugal particle mass analyzer (CPMA), a differential mobility analyzer (DMA), and a single particle mass spectrometer (SPLAT II) was used to obtain a wide range of information on the SIDI PM emissions including particle size distribution (PSD), composition, mass, and dynamic shape factors (DSFs) in the transition ( χ t ) and free-molecular ( χ v ) flow regimes. During the filtration experiments, real-time measurements of PSDs upstream and downstream of the filter sample were used to estimate the filtration performance and the total trapped mass within the filter using an integrated particle size distribution method. The filter loading process was paused multiple times to evaluate the filtration performance in the partially loaded state. The change in vacuum aerodynamic diameter ( d va ) distribution of mass-selected particles was examined for flow through the filter to identify whether preferential capture of particles of certain shapes occurred in the filter. The filter was also probed using different inlet PSDs. Pausing the filter loading process and subsequently performing the filter probing experiments did not impact the overall evolution of filtration performance. Within the present distribution of particle sizes, filter efficiency was independent of particle shape potentially due to the diffusion-dominant filtration process. Particle mobility diameter and trapped mass within the filter appeared to be the dominant parameters that impacted filter performance. Highlights: Effects of inlet particle properties on filtration performance were evaluated. Diffusion was dominated capture mechanism for the size range explore. Average dynamic shape factors were characterized in multiple flow regimes. Size-resolved FE was relatively insensitive to mobility diameter beyond the MPPS. Within observed distribution of shapes, filter efficiency was independent of shape.