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There are many anthropogenic climate change mitigation strategies being adopted worldwide. One of these is the adoption of biodiesel FAME (Fatty Acid Methyl Ester), in transportation. The fuel has been widely promoted as replacement for petroleum diesel because of its potential benefits for life cycle greenhouse gas emissions, carbon dioxide reduction and particulate matter improvements. Presently biodiesel may be made from a wide variety of starting materials, including food waste and agricultural materials such as vegetable oils and greases. The number and variety of possible starting materials continues to increase. Though, there is a limiting factor in the use of FAME, and that is cold weather operability. The regional climate can often influence FAME adoption with resultant economic and environmental implications. Often this cold temperature operability manifests itself as in vehicle fuel filter blocking.

Exhaust Gas Recirculation (EGR) is employed in diesel engines to reduce engine-out NOx emissions. Despite the concerted design efforts of manufacturers, high-pressure Exhaust Gas Recirculation (HP-EGR) systems can be susceptible to fouling as the particulate matter, hydrocarbons and other entrained species deposit from the exhaust gas flow as it cools on its passage through the EGR system. Such deposits can lead to a number of problems including deterioration of emissions, fuel efficiency, performance and drivability, as well as breakdowns. The development of an engine test method to enable the study of the impact of fuel on deposits in the HP-EGR system was reported in 2020. In the test, a 4-cylinder light-duty diesel engine of 1.6L displacement runs at conditions conducive to EGR deposit formation over 24 hours and the impact of fuels on deposit formation is determined through weighing of the EGR system components before and after the test.

Particulate emissions from gasoline direct injection (GDI) engines continue to be a topic of substantial research interest. Forthcoming regulation both in the USA and the EU will further reduce their emission and drive innovation. Substantial research effort is spent undertaking experiments to understand, characterize, and research particle number (PN) emissions from engines and vehicles. Recent advances in computing power, data storage, and understanding of artificial intelligence algorithms now mean that these are becoming an important tool in engine research. In this work a random forest (RF) algorithm is used for the prediction of PN emissions from a highly boosted (up to 32 bar BMEP) GDI engine. Particle size, concentration, and the accumulation mode geometric standard deviation (GSD) are all predicted by the model. The results are analysed and an in depth study on parameter importance is carried out.

Engine research has increasingly focused on emission of sub 23 nm particulates in recent years. Likewise, current legislative efforts are being made for particulate number (PN) emission limits to include this previously omitted size range. In Europe, PN measurement equipment and procedures for regulatory purposes are defined by the particle measurement programme (PMP). Latest regulation drafts for sub 23 nm measurements specify counting efficiencies with a 65% cut-off size at 10 nm (d65) and a minimum of 90% above 15 nm (d90). Even though alternative instruments, such as differential mobility spectrometers (DMS), are widely used in laboratory environments, the interpretation of their sub 23 nm measurements has not yet been widely discussed. For this study, particulate emissions of a 1.0L gasoline direct injection (GDI) engine have been measured with a DMS system for low to medium speeds with two load steps.

The European Particle Measurement Program (PMP) defines the current standard for measurement of Particle Number (PN) emissions from vehicles in Europe. This specifies a 50% count efficiency (D50) at 23 nm and a 90% count efficiency (D90) at 41 nm. Particulate emissions from Gasoline Direct Injection (GDI) engines have been widely studied, but usually only in the context of PMP or similar sampling procedures. There is increasing interest in the smallest particles - i.e. smaller than 23 nm - which can be emitted from vehicles. The literature suggest that by moving D50 to 10 nm, PN emissions from GDI engines might increase by between 35 and 50% but there remains a lot of uncertainty.

Characterization of soot nanoparticle morphology can be used to develop understanding of nanoparticle interaction with engine lubricant oil and its additives. It can be used to help direct modelling of soot-induced thickening, and in a more general sense for combatting reductions in engine efficiency that occur with soot-laden oils. Traditional 2D transmission electron microscopy (TEM) characterization possesses several important shortcomings related to accuracy that have prompted development of an alternative 3D characterization technique utilizing electron tomography, known as 3D-TEM. This work details progress made towards facilitating semi-automated image acquisition and processing for location of structures of interest on the TEM grid. Samples were taken from a four cylinder 1.4 L gasoline turbocharged direct injection (GTDI) engine operated in typically extra-urban driving conditions for 20,284 km, with automatic cylinder deactivation enabled.

Morphology plays an important role in determining behaviour and impact of soot nanoparticles, including effect on human health, atmospheric optical properties, contribution to engine wear, and role in marine ecology. However, its nanoscopic size has limited the ability to directly measure useful morphological parameters such as surface area and effective volume. Recently, 3D morphology characterization of soot nanoparticles via electron tomography has been the subject of several introductory studies. So-called ‘3D-TEM’ has been posited as an improvement over traditional 2D-TEM characterization due to the elimination of the error-inducing information gap that exists between 3-dimensional soot structures and 2-dimensional TEM projections. Little follow-up work has been performed due to difficulties with developing methodologies into robust high-throughput techniques.

The size and morphology of soot particles and agglomerates extracted from lubricating oil drawn from the sump of a diesel engine have been investigated and compared using Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA). Samples were prepared for electron microscopy imaging by both centrifugation and solvent extraction to investigate the impact of these procedures on the morphological characteristics, such as skeleton length and width and circularity, of the obtained soot. It was shown that centrifugation increases the extent of agglomeration within the sample, with 15% of the agglomerates above 200 nm compared to only 11% in the solvent extracted soot. It was also observed that the width of centrifugation extracted soot was typically 10 nm to 20 nm larger than that of solvent extracted soot, suggesting that centrifugation forces the individual agglomerate chains together.

Environmental authorities such as EPA, VCA have enforced stringent emissions legislation governing air pollutants released into the atmosphere. Of particular interest is the challenge introduced by the limit on particulate number (PN) counting (#/km) and real driving emissions (RDE) testing; with new emissions legislation being shortly introduced for the gasoline direct injection (GDI) engines, gasoline particulate filters (GPF) are considered the most immediate solution. While engine calibration and testing over the Worldwide harmonized Light vehicles Test Cycle (WLTC) allow for the limits to be met, real driving emission and cold start constitute a real challenge. The present work focuses on an experimental durability study on road under real world driving conditions. Two sets of experiments were carried out. The first study analyzed a gasoline particulate filter (GPF) (2.4 liter, diameter 5.2” round) installed in the underfloor (UF) position and driven up to 200k km.

Precise, repeatable and representative testing is a key tool for developing and demonstrating automotive fuel and lubricant products. This paper reports on the first findings of a project that aims to determine the requirements for highly repeatable test methods to measure very small differences in fuel economy and powertrain performance. This will be underpinned by identifying and quantifying the variations inherent to this specific test vehicle, both on-road and on Chassis Dynamometer (CD), that create a barrier to improved testing methods. In this initial work, a comparison was made between on-road driving, the New European Drive Cycle (NEDC) and World harmonized Light-duty Test Cycle (WLTC) cycles to understand the behavior of various vehicle systems along with the discrepancies that can arise owing to the particular conditions of the standard test cycles.

Exhaust Gas Recirculation (EGR) is widely used in IC combustion engines for diluting air intake charge and controlling NOx emission. The rate of EGR required by an engine varies by the speed and load and control of the right amount entering the cylinders is crucial to ensure good engine performance and low NOx emission. However, controlling the amount of EGR entering the intake manifold does not ensure that EGR rate will be evenly distributed among the engine's cylinders. This can many times lead to cylinders operating at very high or low EGR rates which contradictory can deteriorate particulate matter and NOx emission. The present study analyses the cylinder-to-cylinder EGR dispersion of a 4 cylinder 2.2L EUROV Diesel engine and its effects on the combustion stability. A 1D-3D coupling simulation is performed using GT-Power and STAR-CCM+ to analyze the effects of intake manifold geometry and EGR supply configuration on the EGR homogeneity and cylinder-to-cylinder distribution.

The focus of this study is to analyse changes in soot particle size along the predicted pathlines as they pass through different in-cylinder combustion histories obtained from Kiva-3v CFD simulation with a series of Matlab routines. 3500 locations representing soot particles were selected inside the cylinder at 8° CA ATDC as soot was formed in high concentration at this CA. The dominant soot particle size was recorded within the size range of 20-50 nm at earlier CA and shifted to 10-20 nm after 20° CA ATDC. Soot particle quantities reduce sharply until 20° CA ATDC after which they remain steady at around 1500 particles. Soot particles inside the bowl region tend to stick to the bowl walls and those remaining in the bowl experience an increase in size. Soot particles that move to the upper bowl and squish regions were observed to experience a decrease in size.

The determination of size distribution of soot particles and agglomerates in oil samples using a Nanosight LM14 to perform Nanoparticle Tracking Analysis (NTA) is described. This is the first application of the technique to sizing soot-in-oil agglomerates and offers the advantages of relatively high rates of sample analysis and low cost compared to Transmission Electron Microscopy (TEM). Lubricating oil samples were drawn from the sump of automotive diesel engines run under a mix of light duty operating conditions. The oil samples were diluted with heptane before analysing. Results from NTA analysis were compared with the outputs of a more conventional analysis based on Dynamic Light Scattering (DLS). This work shows that soot-in-oil exists as agglomerates with average size of 115 nm. This is also in good agreement with TEM analysis carried out in a previous work. NTA can measure soot particles in polydisperse oil solutions and report the size distribution of soot-in-oil aggregates.

The influence of size and concentration of carbon nanoparticle on the viscosity of an SAE 5W-30 lubricant oil has been investigated experimentally. Data were collected for oil samples drawn from sump of light duty automotive diesel engines. The average size of soot particles in the used oil samples was in the range of 180-320nm with concentrations ranging from 0 to 2 percentage by weight (wt. %.). A Brookfield DV-II Pro rotary viscometer was used to measure dynamic viscosity at low shear rates and temperatures of 40°C and 90°C. Nanoparticle concentration and particle size distribution were evaluated using Thermo-Gravimetric Analysis (TGA) and Dynamic Light Scattering (DLS) respectively. The viscosity of suspensions of graphite powder in lubricant oil was also investigated for concentrations ranging from 0 to 2 wt. %. The results show that dynamic viscosity increases with increasing soot content and decreasing temperature.

Soot formation and distribution inside the cylinder of a light-duty direct injection diesel engine, have been predicted using Kiva-3v CFD software. Pathlines of soot particles traced from specific in-cylinder locations and crank angle instants have been explored using the results for cylinder charge motion predicted by the Kiva-3v code. Pathlines are determined assuming soot particles are massless and follow charge motion. Coagulation and agglomeration have not been taken into account. High rates of soot formation dominate during and just after the injection. Oxidation becomes dominant after the injection has terminated and throughout the power stroke. Computed soot pathlines show that soot particles formed just below the fuel spray axis during the early injection period are more likely to travel to the cylinder wall boundary layer. Soot particles above the fuel spray have lesser tendency to be conveyed to the cylinder wall.

The effect of compression ratio on sensitivity to changes in start of injection and air-fuel ratio has been investigated on a single-cylinder DI diesel engine at fixed low and medium speeds and loads. Compression ratio was set to 17.9:1 or 13.7:1 by using pistons with different bowl sizes. Injection timing and air-to-fuel ratio were swept around a nominal map point at which gross IMEP and NOx values were matched for the two compression ratios. It was found that CO, HC and ISFC were higher at low compression ratio, but the soot/NOx trade-off improved and this could be exploited to reduce the fuel economy penalty. Sensitivity to inputs is generally similar, but high compression ratio tended to have steeper response gradients. Reducing compression ratio to 13.7 gave rise to a marked degradation of performance at light load, producing high CO emissions and a fall in combustion efficiency. This could be eased by reducing rail pressure, but the advantage in smoke emission was lost.

In a context of global warming and our needs to reduce CO2 emissions, building envelopes will play an important role. A new imperative has been put forth to architects and engineers to develop innovative materials, components and systems, in order to make building envelopes adaptive and responsive to variable and extreme climate conditions. Envelopes serve multiple functions, from shielding the interior environment to collecting, storing and generating energy. Perhaps a more recent concern of terrestrial habitats is permeability and leakages within the building envelope. Such air tight and concealed envelopes with zero particle exchange are a necessity and already exist in regard to space capsules and habitats. This paper attempts to acknowledge existing and visionary envelope concepts and their functioning in conjunction with maintaining a favourable interior environment. It introduces several criteria and requirements of advanced façades along with interior pressurization control.