PM Characteristics Research Articles

Relationship between PM1.0 and PM2.5 in urban and background areas of Republic of Korea

Seasonal intensive measurements of atmospheric particulate matter with aerodynamic diameters less than or equal to a nominal 1.0 μm (PM1.0) and 2.5 μm (PM2.5) were conducted at an urban (Seoul, SL) and a background site (Baengnyeong, BN, an island about 200 km from SL) in Korea to fully understand the characteristics of PM1.0 within PM2.5, as well as the differences in PM characteristics between urban and background sites. A single-channel particle sampler with PM1.0 and PM2.5 cyclones was used to collect the samples simultaneously. Eight ions (Cl−, NO3−, SO42−, Na+, NH4+, K+, Ca2+, and Mg2+), carbonaceous components (organic carbon (OC) and elemental carbon (EC)), and ten elements (As, Cd, Cu, Zn, Pb, Cr, Mn, Fe, Ni, and Al) were analyzed. The ratio of PM1.0 to PM2.5 mass concentration was approximately 80%, and the coefficients of determination (r2) between PM1.0 and PM2.5 was higher than 0.95 at both sites. PM1.0 was primarily responsible for the chemical composition of PM2.5. At both sites, OC was the most prevalent component of PM1.0 and PM2.5, followed by NO3−, SO42−, NH4+, and EC. According to source apportionment of the PMF model, PM1.0 and PM2.5 were explained from nine and eight factors at both SL and BN, respectively. At both sites, the significantly larger proportion of the factors of PM1.0 and PM2.5 were secondary inorganic aerosol and the contributions of sources for PM2.5 in SL and BN were comparable to those of PM1.0. This study confirmed that (1) PM1.0 and PM2.5 showed similar characteristics at both SL and BN and (2) PM1.0 contributed significantly to the chemical composition and sources of PM2.5 both in SL and BN, implying that PM1.0-2.5 had a minor impact on PM2.5 in these two sites. Thus, though further studies are needed, it is likely that the current air quality management direction for PM2.5 is also effective in managing PM1.0 in Korea.

Structural Multi-Tooth Modification of Hybrid-Excited Doubly Salient Dual-PM Machine for Torque Production Improvement

A hybrid-excited doubly salient dual-PM machine (HE-DSDPM) was presented by using the structural multi-tooth modification for an improvement of torque production. The multi-tooth structure modification of HE-DSDPM was clearly described. The PM and stator arcs were further examined for structural optimization. The electromagnetic performance including magnetic flux distribution, flux linkage, back-electromotive force (back-EMF), total harmonic distortion (THD), cogging torque and electromagnetic torque, was investigated with various field current under the same structural constraint. The simulation based on 2-D finite element analysis was used to validate all electromagnetic performance. The results showed that the proposed multi-tooth HE-DSDPM provides the best stator/rotor combination, the appropriate PM characteristics and the enlarged winding slot area. This proposed structure produces better overall electromagnetic performance because of its improved symmetrical magnetic flux path and greater flux regulation quality. In particular, it can generate a larger average torque of 26.18% with the lower ripple torque of about 4% compared to the conventional structure at no field current since the good back-EMF profile and low cogging torque. The largest variance of the torque percentage is occurred when excited by different field currents for the proposed multi-tooth HE-DSDPM. Hence, modification of multi-tooth structure could be beneficial in the electrical machine design of other types of doubly salient structures.

Reducing the Effect of High Sulfur Content in Diesel Fuel on NO x Emissions and PM Characteristics Using a PPCI Mode Engine and Gasoline-Diesel Blends.

Recently, high sulfur content in diesel fuel is one of the main problems that have an effect on combustion and emission characteristics. Iraq is one of many countries in the world that use diesel fuel with high sulfur content. Therefore, the partially premixed combustion ignition (PPCI) concept and different blend ratios of gasoline–diesel (GD30, GD40, and GD50) were suggested in this study to reduce the sulfur content in the fuel, improve the engine performance, and reduce the exhaust emissions. The combined effect of adding gasoline to the diesel fuel and manipulating the fuel injection timings can lead to better and clean combustion. For the same engine operating conditions, it is found that the brake thermal efficiency (BTE) decreases during the combustion of GD blends in comparison with diesel fuel. Furthermore, the results of using GD blends showed a small reduction in brake-specific fuel consumption (BSFC) compared to the conventional diesel fuel. The exhaust gas temperature reduces from the combination effect of PPCI mode and GD blends, which in turn decreases the NOx emission concentration under variable conditions of engine loads and speeds. It is indicated that the NOx emissions significantly decreased during the combustion of GD30, GD40, and GD50 blends by 25.94, 50.9, and 84%, respectively, in comparison with diesel fuel. In addition, higher reduction in CO and HC formation was obtained during the combustion of conventional fuel in comparison with the combustion of GD blends. The results showed that the number and concentration of PM reduced more when using GD blends and PPCI mode. The average particle diameter (dp) decreased from the combustion of GD blends in comparison with diesel fuel. The particle diameter of the GD blend was varied from 25 to 26 nm compared to those of diesel fuel of 35 and 36 nm under the same engine operating conditions. Reducing the sulfur content in GD blends contributed to a clear reduction in SO2 and H2S emissions by 57.85 and 50.12%, respectively.

Elemental analysis of aircraft engine smoke number filter samples with micro-PIXE

To extract information on elemental components and PM characteristics from smoke number (SN) filter paper, we were performed elemental analysis by micro-PIXE. As a result of elemental analysis of the SN filter, information on the elemental composition of jet engine exhaust PM was obtained. Regarding the SN filter, jet engine exhaust PM have been collected for each difference in engine thrust of various aircraft engines at aircraft turbine engines test cells around the world. By periodically analyzing the elemental composition of such the SN filter, it is possible to grasp the characteristics of the emission PM of each aircraft engine and the transformation of the elemental composition of the emission PM with the passage of time of the jet engine. This was thought to lead to the evaluation of jet engine.

Influence of post-injection strategies and CeO2 nanoparticles additives in the C30D blends and diesel on engine performance, NOX emissions, and PM characteristics in diesel engine

This study investigates the influences of post-injection (PI) strategy and adding two concentrations (50 and 100 mg/l) of Cerium oxide (CeO2) nanoparticles to the diesel-castor oil (C30D) and diesel on engine performance, NOX emissions, and characteristics of PM. The adding CeO2 nanoparticles to the C30D and diesel were tested under with PI and W/O PI strategy. The results indicated that the BTE increased by 9.42% from the blends of C30D + CeO2 compared with diesel + CeO2 under with and without PI strategy. Furthermore, the BSFC decreased by 16.46% from C30D + CeO2 nanoparticles compared with diesel + CeO2 nanoparticles. The cylinder pressure and ROHR increased with addition of CeO2 nanoparticles to the C30D compared to the C30D, diesel, and diesel + CeO2 under different PI strategy. For the same CeO2 concentration, the results showed that the NOX emissions decreased by 10.64% when adding 100 mg/L of CeO2 to the C30D compared with diesel + CeO2 nanoparticles by 8.73%. The adding 50 and 100 mg/L of CeO2 to the C30D reduced the concentration of PM by 28.62 and 42.72%, respectively, compared C30D without additives. Besides, the adding both concentrations of CeO2 to the diesel decreased the concentration of PM by 16.74 and 24.83%, respectively, compared without additives into the diesel fuel. It is found that the size of primary particles (dpo ) slightly increased with addition of CeO2 nanoparticles to the C30D and diesel under with and W/O PI strategy. The data of this experiment revealed that introduce the PI strategy and 100 mg/L of CeO2 nanoparticles gives positive effect on engine performance, NOX emissions, and total concentration of PM. Highlights The cylinder pressure and rate of heat release increased with addition of CeO2 nanoparticles to the C30D. Adding nanoparticles to C30D decreased the BSFC and increased BTE compared with those of the C30D and diesel without additives. The blends of C30D + CeO2 decreased the concentration of PM. Adding different concentration of CeO2 nanoparticles increased the average particle diameter. The NOX emissions decreased with addition CeO2 nanoparticles to the C30D and diesel.

Reactive oxygen species (ROS) activity of fine particulate matter health impacts in Addis Ababa, Ethiopia

Previous studies in Addis Ababa, Ethiopia, focused on PM characteristics and sources, but PM's biological activity in this area has not been adequately investigated. In this study, cellular and acellular ROS activities were measured to assess PM toxicity. PM2.5 samples in Addis Ababa were collected from November 2015 to November 2016 and their chemical composition was analyzed (organic and elemental carbon (OC/EC), ions, elements, and organic molecular markers). PM-induced ROS activity was measured in vitro in alveolar macrophage cells and using the acellular DTT assay. PM2.5 in Addis Ababa primarily consisted of primary pollutants (e.g., EC, water-insoluble OC). Annual average cellular ROS activities (±SD) were 46.5 ± 15.5 μg Zymosan/m3 and 995 ± 403 μg Zymosan/mg PM (normalized to air volume and PM2.5 mass, respectively), with no clear seasonal variations. The annual average DTT consumption rates (±SD) were 2.35 ± 0.83 nmol/min/m3 and 51.9 ± 17.6 nmol/min/mg PM, respectively, and were also similar throughout the year. Only the monthly air volume-based ROS activity had a similar trend to monthly mass concentration. Compared to other major cities worldwide, Addis Ababa PM2.5 had much lower ROS activity with no strong seasonal trends, paralleling the lack of seasonal changes in PM composition and sources. Poor correlations were observed between ROS activity and all components except mobile source tracers. This difference might be due to lower secondary aerosol content in PM2.5 in Addis Ababa than in other cities.

Quantitative Comparison of Methods to Assess the Airborne Particulate Matter Retention Capacity of Leaves

The objective of this study was to explore the differences of five methods for evaluating the PM retention capacity of leaves based on the same experimental materials and leaf area measurement method and to summarize the advantages and disadvantages of each method. In this study, four tree species (Pinus tabuliformis, Platycladus orientalis, Ginkgo biloba, and Platanus occidentalis), which are common in Beijing and have greatly different leaf characteristics, were selected as the research objects. The mass subtraction method (MS), the membrane filter method (MF), the aerosol regenerator method(AR), the scanning electron method (SEM), and the elution weighing method coupled with a particle size analysis based on ultrasonic cleaning (ultrasonic-EWPA) were used to evaluate the PM retention capabilities and characteristics of the leaves of the four tree species. The total time needed and the total cost were measured simultaneously during the evaluation process. The results showed that although the values of PM retention efficiency obtained by different methods were quite different, the ranks of the efficiency of four tree species obtained by different methods were the same or partially the same. Additionally, the results obtained by the methods with the same or similar principles were more overlapped (AR and SEM had the most overlapped results). In addition, 89% of the species ranks of the same index obtained by each method were P. orientalis > P. tabuliformis > P. occidentalis > G. biloba, and the remaining 11% were P. occidentalis > G. biloba > P. orientalis > P. tabuliformis. Among the five methods, ultrasonic-EWPA was the one with the largest number of indexes and the highest cost, and MS was the one with the least number of indexes and the lowest cost. The one that needed most time was MF, while the one that needed the least time was AR. ultrasonic-EWPA and SEM are high input and high output methods. That is to say, although they needed more time and cost, they can prove more information; however, MS was opposite, which resulted in less information but lower time and cost needed. So, it is suitable for roughly evaluating the total PM retention capacities of trees; MF had a medium amount of information, low cost, but required too much time, which needs to be weighed and balanced before selecting this method. The AR method had strict requirements for equipment and parameters and should be used with caution. The results of this study can provide a comprehensive and detailed scientific basis for researchers to choose specific methods in the future.

A state-of-the-art review on emission characteristics of SI and CI engines fueled with 2,5-dimethylfuran biofuel.

Currently, the considerable decline in fossil fuel resources and the high rise in vehicle emissions have prompted researchers and governments to formulate strategies for sustainable energy development. In addition to imposing strict laws, promoting sustainable energy sources such as the development of new types of non-fossil fuels has been considered a suitable direction for the roadmap to healing the Earth's environment. Biomass sources have affirmed huge potentials in the production of biofuels. In the pathway of searching renewable biofuels, it is found that that 2,5-dimethylfuran (DMF) can become a promising fuel because it is synthesized from lignocellulose biomass, which is an available feedstock for the production of prospective fuels. Indeed, recent review studies have focused in great detail on engine performance evaluation using DMF but seemed to have gaps in emission characteristics. In this work, the controversial issues of emissions from spark and compression ignition engines during the DMF combustion were completely assessed. Indeed, the mechanism of formation and oxidation of DMF compounds during combustion was clearly described to serve as the basis for analyzing and comparing the pollution emission behavior of different fuels. More importantly, gaseous emissions, PM characteristics, and soot tendency from spark and compression ignition engines were thoroughly evaluated on the basis of the experimental and numerical data. In general, DMF has shown outstanding advantages upon emissions compared to fossil fuels; however, the impacts of DMF on the engine durability and fuel system should be further investigated to have a comprehensive analysis of this biofuel class.

PANDA Type Four-Core Fiber With the Efficient Use of Stress Rods

We design a panda type four-core fiber with a comparable optical property of the polarization maintenance single mode fiber (PM-SMF) and can support 8 non-polarization-degenerate eigenmodes with a birefringence of approximate 3.24 × 10 -4 over the wavelength range from 1288 to 1630 nm. In particular, only four stress rods are efficiently used to achieve the PM characteristics for each core, in comparison with traditional design of panda type PM-SMF. Meanwhile, we identify that the optimal configuration of stress rods can not only enhance the birefringence, but also further suppress the crosstalk (XT) between two primary eigenstate of polarization (ESOP) arising in adjacent cores, although the corresponding XT at secondary ESOP remains unchanged. Moreover, our numerical results show that both chromatic dispersion (CD) together with mode field diameter (MFD) and the bending sensitivity are consistent among four cores. We believe that such specialty multi-core fiber is ideal for compact and cost-effective fiber-optic gyroscope (FOG) application, besides the potential in the MIMO-free spatial division multiplexing (SDM) interconnection.

Design Optimization of Double-Sided Permanent-Magnet Axial Eddy-Current Couplers for Use in Dynamic Applications

This paper deals with analytical model extraction and also optimization of the double-sided PM axial eddy-current couplers, which are one of the best-known couplers used in dynamic applications. To this end, a rather accurate steady-state model was extracted using a magnetic equivalent circuit method, which is capable of taking into account geometrical parameters and material properties exclusive of iron saturation, the PM characteristics, and the conductive-sheet heating constraint. Electrical time constant of the coupler (due to the inductance property of the conductive sheet), which is an important quantity in the dynamic behavior, is also calculated analytically. Furthermore, by introducing a specific dynamic application, the best set of components for the coupler is obtained through genetic algorithm with respect to some significant dynamic criteria such as system bandwidth. Finally, the results are validated using FEM and experimental tests.

Linearity-Enhanced Doherty Power Amplifier Using Output Combining Network With Predefined AM–PM Characteristics

In this paper, a new method is proposed to synthesize a linearity-enhanced Doherty power amplifier (DPA) without deteriorating its efficiency. This method determines the combiner network parameters so that a predefined amplitude-to-phase (AM–PM) characteristic is produced while maintaining proper load modulation and consequently good back-off efficiency. The predefined AM–PM characteristic is chosen to be the inverse of the main transistor to enhance the overall DPA linearity. For proof-of-concept validation purposes, a linearity-enhanced DPA circuit prototype is designed to provide linear overall AM–PM characteristics over the frequency band of 4.7–5.3 GHz. Meanwhile, its input matching network is designed to minimize the amplitude-to-amplitude (AM–AM) distortion by properly selecting the source impedances. The measurement results of the DPA prototype under continuous-wave stimuli reveal AM–PM and AM–AM characteristics with maximum phase and gain compression/expansion below ±1° and ±0.25 dB, respectively, when the input power level is swept up to a saturation level of 39 dBm over 4.9–5.3 GHz. Furthermore, when driven with carrier aggregated signals with modulation bandwidths of up to 160 MHz and a peak-to-average power ratio equal to 7.4 dB, the DPA prototype maintains an adjacent channel leakage ratio of better than −40 dBc with a drain efficiency in the excess of 40% and an average output power of 32 dBm, without resorting to any additional linearization schemes. The proposed DPA methodology paves the road for the application of the DPA technique to 5G massive multiple-input and multiple-output transmitters with relaxed linearity requirements as it avoids the extra complexity and power consumption overhead associated with dedicated linearization schemes.

Trend of biodiesel feedstock and its impact on biodiesel emission characteristics

Feedstock for biodiesel production has changed over time and it varies depending on regions. Reports and journal articles on biodiesel feedstock resources over the last decade from 2006 to 2016 were reviewed in this article. The regional trends still maintain as the USA and the EU still predominantly use soybean oil and rapeseed oil, respectively, and palm oil is the major source of biodiesel in Asia. It is expected that the food‐crop based biodiesel will continue to be dominant for the next decade. However, it was found that uses of animal fats and used cooking oil are increasing both in the USA and the EU. Because of the increasing diversity in feedstock inputs to biodiesel, it is necessary to better understand the effects of feedstock characteristics on engine performance and emissions. In this review, we limit the reports on biodiesel emissions to those who used 100% biodiesel combusted in a one‐cylinder, four‐stroke, direct injection engine set up in a laboratory. All the emission results were obtained from the same or similar engine conditions to fairly compare them. CO, CO2, NOx, and PM emissions are compared between the biodiesels derived from soybean oil, rapeseed oil, palm oil, jatropha oil, used cooking oil, animal fats, and algal oil. It was found that more emission studies are needed for algal biodiesel. More in‐depth studies are necessary for PM characteristics including the compositions of trace metals, elemental and organic carbon. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 7–19, 2018

PM and NOx reduction characteristics of LNT/DPF+SCR/DPF hybrid system

The purpose of study is to investigate effects and differences when applying a hybrid system of LNT/DPF+SCR/DPF catalysts and LNT/DPF in diesel engine. A lean NOx trap (LNT) catalyst was prepared using an impregnation method, and a selective catalytic reduction (SCR) catalyst was prepared through an ion-exchange method. Each catalyst was dip-coated in an advanced cordierite-diesel particulate filter (AC-DPF). Its de-NOx and de-PM characteristics were analyzed using a model gas test-rig. As a result, NOx conversion of the hybrid system was higher than that of single LNT/DPF system. Because of NO2 and NH3, which is formed in a LNT/DPF in the rich air-fuel ratio duration is used a reductant for SCR/DPF catalyst of the hybrid system. Along with SCR/DPF, an increase in NOx conversion occurs through HC-SCR reaction because fuel as a dosing reductant is used not only for LNT/DPF but also for SCR/DPF. For de-PM characteristics, the light-off temperature 50, which is 50% of the oxidizing temperature of the PM, is 598 °C in the hybrid system and 627 °C in LNT/DPF. Moreover, the rate of PM oxidation over the hybrid system is higher than that of LNT/DPF because the oxidizing power of SCR/DPF was additionally added into the hybrid system.

Preliminary investigation of PM1, PM2.5, PM10 and its metal elemental composition in tunnels at a subway station in Shanghai, China

In this study, real-time monitoring campaigns were conducted in two tunnels (Line A and Line B) at a subway station in Shanghai, including temperature, relative humidity, PM1, PM2.5 and PM10, in order to understand the climate and PM characteristics in the transportation microenvironment. In addition, collected floor dust particles in the tunnel were analyzed by ICP for their metal elemental composition. Strong correlations occurred between all PM levels and meteorological parameters in the tunnel of Line A (with platform screen doors), in comparison with the weak correlations between such parameters in the tunnel of Line B (without platform screen doors). PM2.5 and PM10 between peak hours and off-peak hours for both lines presented significant differences (p<0.05), respectively. Nevertheless, PM1 showed a different pattern, with p>0.05 for Line A and p<0.05 for Line B, respectively. In addition, statistical results concluded that PM had an evident weekly variation for both lines. Friday was the highest day of all particulate matters in monitoring periods for both lines. Ratios of PM1/PM10 and PM2.5/PM10 were high when trains were out of service and low when trains were in service. Relative abundance of metal elements detected from floor dust particles proved that floor dust particles in tunnels might be a major source of airborne PM in the subway microenvironments, with Fe as the most abundant metal element, followed by Ca, Al, Mg, Mn, Zn, Cu, Cr, Ni, Pb and Hg.

PM emissions measurements of in-service commercial aircraft engines during the Delta-Atlanta Hartsfield Study

This paper describes the results of the physical characterization of aircraft engine PM emission measurements conducted during the Delta-Atlanta Hartsfield Study at the Hartsfield-Jackson Atlanta International Airport. Engine exit plane PM emissions were sampled from on-wing engines on several in-service commercial transport aircraft from the fleet of Delta Airlines. The size distributions were lognormal in nature with a single mode. The geometric mean diameter was found to increase with increasing engine thrust, ranging from 15 nm at idle to 40 nm at takeoff. PM number- and mass-based emission indices were observed to be higher at the idle conditions (4% and 7%), lowest at 15%–30% thrust, and then increase with increasing thrust. Emissions measurements were also conducted during an advected plume study where over 300 exhaust plumes generated by a broad mix of commercial transports were sampled 100–350 m downwind from aircraft operational runways during normal airport operations. The range of values measured at take-off for the different engine types in terms of PM number-based emission index was between 7 × 1015–9 × 1017 particles/kg fuel burned, and that for PM mass-based emission index was 0.1–0.6 g/kg fuel burned. PM characteristics of aircraft engine specific exhaust were found to evolve over time as the exhaust plume expands, dilutes with ambient air, and cools. The data from these measurements will enhance the emissions inventory development for a subset of engines operating in the commercial fleet and improve/validate current environmental impact predictive tools with real world aircraft engine specific PM emissions inputs.

Simple nonlinear MEC-based model for sensitivity analysis and genetic optimization of permanent-magnet

Purpose – The purpose of this paper is to develop an effective, yet simple analytical framework for optimization of permanent-magnet synchronous machines. Also, single/multi-objective optimizations are performed for a case-study machine with surface-mounted permanent magnets. Design/methodology/approach – First, an accurate magnetic equivalent circuit is developed which takes all the material such as iron saturation and PM parameters into account. Then, through a Fourier analysis, it is combined with the d-q model of PM synchronous machines to achieve an optimization framework including the developed torque, back-EMF and a number of design considerations. Finally, a genetic algorithm (GA) is employed in the single/multi-objective design optimizations, which offers several design characteristics upon different desired outcomes. Findings – An analytical design framework for the optimization of permanent-magnet synchronous machines is developed in this paper that can effectively account for all material properties such as iron saturation and PM characteristics, and take into account the design considerations, all of which are shown as superiorities of the proposed approach over the existing method. In addition, the proposed framework is relatively simpler in terms of implementing. The model is verified by employing finite element method. Moreover, sensitivity analysis is carried out to investigate the influence of the design parameters on the machine performance, which provides valuable information for the designer of such devices. Finally, a GA is utilized to perform single/multi-objective optimization schemes whose objectives are minimizing the torque ripples, back-EMF total harmonic distortion and PM volume. Originality/value – The proposed framework is new approach that could be employed in the design optimization of PM synchronous machines. Contrary to existing method, it is simpler and more effective in taking the material properties such as iron saturation and PM characteristics into account.

Design optimization of double-sided permanent-magnet radial-flux eddy-current couplers

It is essential for engineers to improve overall performance of electromagnetic devices. In this paper, single/multi-objective design optimization of double-sided permanent-magnet radial-flux eddy-current couplers is carried out. To this end, an analytical model of such devices is developed by combining conventional magnetic equivalent circuit techniques with Faraday's and Ampere's laws. The model is capable of easily dealing with complex geometries and material properties such as iron saturation and the PM characteristics as well as the associated design constraints so that the designs that are more realistic can be achieved. A genetic algorithm that enjoys a flexible objective function is finally adopted to find the optimal machine parameters. Finite-element method is also employed to verify the results.

Analysis on dynamic characteristics of reflective semiconductor optical amplifier based on a memory polynomial model

This article presents the AM–AM and AM–PM characteristics of a bulk reflective semiconductor optical amplifier (RSOA) based on a memory polynomial model. The coefficients of the behavioral model are extracted and validated by experimental results. The nonlinearity and memory effects of RSOA are demonstrated by its dynamic AM-AM and AM-PM characteristics. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:805–808, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26636

PM Characteristics from Pool Diffusion Flame with Surrogate Diesel Fuel

Reduction of nanometer size particulate matter (Nano-PM) in diesel exhaust is important for its harmful potential to health. Therefore it is necessary to understand effect of fuel compositions on PM characteristics in terms of fuel side reduction of PM. However, it is not easy to understand mechanism of diesel PM formation by investigating diesel combustion due to its complicated fuel composition. Purpose of the study is to develop surrogate diesel fuel. A laboratory scale PM generator was applied to generation of nano-PM with diesel and surrogate diesel fuel. In order to evaluate similarity of PM characteristics with diesel and surrogate diesel fuel, Scanning Mobility Particle Sizer (SMPS3034) was used to measure the size distribution of PM. Three kinds of surrogate diesel fuel containing n-decane and α-methylnaphthalene were made with changing their mixing ratio. Flame length for fuel consumption rate and PM number distribution of PM with surrogate diesel fuels were compared with those of fuel.

Particle Number and Size Distribution from a Small Displacement Automotive Diesel Engine during DPF Regeneration

The aim of this work is to analyze particle number and size distribution from a small displacement Euro 5 common rail automotive diesel engine, equipped with a close coupled aftertreatment system, featuring a DOC and a DPF integrated in a single canning. In particular the effects of different combustion processes on PM characteristics were investigated, by comparing measurements made both under normal operating condition and under DPF regeneration mode. Exhaust gas was sampled at engine outlet, at DOC outlet and at DPF outlet, in order to fully characterize PM emissions through the whole exhaust line. After a two stage dilution system, sampled gas was analyzed by means of a TSI 3080 SMPS, in the range from 6 to 240 nm. Particle number and size distribution were evaluated at part load operating conditions, representative of urban driving. Finally, particle number and size distribution at engine outlet were also evaluated fuelling the engine with neat FAME (Fatty Acid Methyl Ester), in order to evaluate the impact of alternative fuels on PM characteristics during normal operating conditions. Results show that under normal operating conditions the engine and DOC outlet particle number and mass size distributions appeared to be extremely similar, while the DPF exhibited high values of filtration efficiency on a particle number basis also in the nanoparticles range. Regeneration mode caused a particle number increase of an order of magnitude, with a substantial shift of the number distribution peaks towards larger diameters. The particle number across the DOC showed a remarkable reduction for particles larger than 40nm, with one order of magnitude reduction in concentrations. Fuelling the engine with FAME leads to a remarkable reductions both in terms of particle number and mass (up to 80% and 90% respectively) under normal operating conditions