Review on characterization of nano-particle emissions and PM morphology from internal combustion engines: Part 1

Thermomagnetic Behavior of Magnetic Susceptibility—Heating Rate and Sample Size Effects

“…Temperaturedependent magnetic susceptibility behavior monitored in the temperature range 20-700 • C gives possibilities for determination of the specific Curie temperature of the ferromagnetic mineral present in the sample, which for the major Fe-containing phases in natural materials falls within this range (Hunt et al, 1995). Kinetics of phase transitions is especially sensitive to grain size of the mineral compound (Navrotsky et al, 2010;Chen, 2013). Moreover, natural samples are complex systems, containing different mineral phases, organic compounds and liquids.…”

Nanoparticle Filtration Characteristics of Advanced Metal Foam Media for a Spark Ignition Direct Injection Engine in Steady Engine Operating Conditions and Vehicle Test Modes

“…Generally, PM size distributions are classified as tri-modal, and they primarily consist of nucleation, accumulation, and coarse modes. These modes are distinguished by the particle diameter [7][8][9][10]. The particle size distribution at the engine-out sampling position was bi-modal with 10 nm < dp < 30 nm from 1500 rpm, BMEP 1.5 bars to 2000 rpm, BMEP 2.0 bars, and it consisted of accumulation mode particles with 40 nm < dp < 100 nm formed at 2000 rpm, BMEP 4.0 bars and 3500 rpm, BMEP 4.0 bars.…”

“…The levels of particle number emissions were closely related with the engine coolant temperature and the driving conditions of the vehicle. In the wall-guided GDI engine, the direct accumulation of injected fuel on a piston leads to rich combustion in the piston crown area, but an incomplete combustion results in soot formations [6][7][8]10,17,18,20,27,39,43]. Low vehicle speed and long idle times in phase 1 of the FTP-75 mode impact on late increment of the engine coolant, combustion chamber wall, and exhaust system temperatures.…”

“…State-of-the-art GDI engines combined with boosting technology offer higher specific power, lower fuel consumption and faster response than conventional port fuel injection (PFI) engines [3][4][5][6][7]. In spite of these many advanced technologies, many studies have indicated that the mixture preparation schemes and combustion mechanisms of the GDI engine emit significantly higher amounts of particulate matter (PM) than the traditional PFI engines or diesel engines that have been equipped with particulate filters, especially during the cold-start phase and at high acceleration points [5,6,[8][9][10][11][12][13][14][15]. The fuel impingement on the piston bowl and the cylinder liner is responsible for particle formation, so comprehensive approaches or optimization of the injector location, the combustion chamber shape, and improved engine control strategies need to be considered to reduce the formation of nanoparticles in GDI engines [16][17][18][19][20].…”

“…Therefore, a cost-effective gasoline particulate filter (GPF) can be adopted for GDI vehicles to reduce the nano-PM emissions to satisfy future PN emission regulations [10,27,[29][30][31][36][37][38][39]. The physical characteristics of volume, space velocity, pressure drops, exhaust temperature for natural regeneration, and particle-filtering efficiency, including sub-23 nm particles that do not negatively affect vehicle exhaust emissions and fuel efficiency, should be considered for optimized performance [5,10,25,27,30,[36][37][38][39][40][41][42][43].…”