Diesel particulate matter (PM) produced from Ultra Low Sulfur Diesel (ULSD), Soy-derived B20 and Animal fat-derived B20 was collected at two engine operating conditions. Gravimetric analysis showed the PM emissions to depend on both fuel and engine operating condition. B20 fuels exhibited higher PM emissions at low load conditions, but lower PM emissions under high load conditions. The differences between the operating conditions were less significant for B20 fuels than for ULSD. Elemental Carbon analysis revealed the B20 PM to contain greater proportions of organic carbon, which may improve diesel particulate filter (DPF) regeneration. Finally, TEM images showed considerable differences between ULSD and B20 soot at low engine loads. The B20 soot displayed a more disordered arrangement of graphene layers. At higher loads, the differences are subtle, but the B20 PM still displayed a more amorphous structure. There was little difference between the Soy and Animal fat-derived B20 soot.

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This work is primarily comprised of five self-contained papers. Three papers are applications oriented. A common element in the first three papers is that micro-perforated panels (MPP), the permeable membranes in diesel particulate filters, and a source impedance are all modeled as a transfer impedance. The first paper deals with enhancing the performance of micro-perforated panels by partitioning the backing cavity. Several different backing schemes are considered which enhance the performance without increasing the total volume of the MPP and backing. In the second paper, a finite element modeling approach is used to model diesel particulate filters below and above the plane wave cutoff frequency. The filter itself is modeled using a symmetric finite element model and results are compared to plane wave theory. After the transfer matrix of the filters is known, it is used in three-dimensional finite and boundary element models. The third paper is a tutorial that shows how a source impedance can be modeled using transfer impedance approaches in finite element analysis. The approach used is useful for better understanding the resonance effects caused by pipes upstream and downstream of the exhaust. The fourth paper examines the best practice for the two-load transmission loss measurement. This method was integral to obtaining the measurements for validating the diesel particulate filter models. The fifth paper proposes transmission and insertion loss metrics for multi-inlet mufflers. It is shown that the transmission loss depends on the amplitude and phase relationship between sources (at the inlets) whereas insertion loss depends on both the source strength and impedance for each inlet.

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Indiana University-Purdue University Indianapolis (IUPUI) / The Electrical capacitance tomography (ECT) method has recently been adapted to obtain tomographic images of the cross section of a diesel particulate filter (DPF). However, a soot mass estimation algorithm is still needed to translate the ECT image pixel data to obtain soot load in the DPF. In this research, we propose an estimation method to quantify the soot load in a DPF through an inverse algorithm that uses the ECT images commonly generated by a back-projection algorithm. The grayscale pixel data generated from ECT is used in a matrix equation to estimate the permittivity distribution of the cross section of the DPF. Since these permittivity data has direct correlation with the soot mass present inside the DPF, a permittivity to soot mass distribution relationship is established first. A numerical estimation algorithm is then developed to compute the soot mass accounting for the mass distribution across the cross-section of the DPF as well as the dimension of the DPF along the exhaust flow direction. Firstly, ANSYS Electronic Desktop software is used to compute the capacitance matrix for different amounts of soot filled in the DPF, furthermore it also analyzed different soot distribution types applied to the DPF. The Analysis helped in constructing the sensitivity matrix which was used in the numerical estimation algorithm. Experimental data have been further used to verify the proposed soot estimation algorithm which compares the estimated values with the actual measured soot mass to validate the performance of the proposed algorithm.

The diesel particulate filter captures particulate matter that is produced in the diesel engine. A small fraction of particulate matter is comprised by ash forming matter. When the combustible fraction of particulate matter is removed from the filter, the ash, which is incombustible, remains. The accumulation of ash in the diesel particulate filter increases fuel consumption and shortens the lifetime of the filter. The study of ash accumulation in filters is mostly dependent on field tests; an expensive and time-consuming process. To establish a more economical testing method, both in terms of time and cost, the accumulation of ash in the filter has to be accelerated. Hence, a literature study to determine the important parameters affecting ash formation and deposition pattern has been performed and the results are presented in this thesis. Moreover, a design proposition for an accelerating ash accumulation test rig is presented. The rig design allows for the control of exhaust gas temperature and velocity, soot production rate and morphology, intervals between regeneration as well as position and method of ash forming matter introduction. A burner is used for the production of soot and ash, and the exhaust gases are guided to the filter by a blower placed downstream the filter. The blower compensates for the pressure drop, allowing the gas flow to be constant. For a more precise temperature control, a heater is placed before the inlet of the filter. The different ash production methods that can be tested are the injection of oil in the burner’s flame, the injection of oil in the gas stream, and the use of fuel doped with oil. By replacing the burner with a particle feeder, the rig can also fill the filter with ash; artificial, or collected from actual filters. Additionally, a set of considerations is provided to enable the accurate component specifications/ characterisation. The design is following a modular concept, i.e. the components’ position can change to accommodate various research goals. / Ett dieselpartikelfilter fångar partiklar som genereras vid förbränningen i en dieselmotor. En bråkdel av partiklarna består av askbildande material. När den brännbara delen avlägsnas från filtret återstår enbart aska (som inte är brännbar). Ackumuleringen av aska i ett dieselpartikelfilter ökar bränslekonsumtionen och förkortar filtrets livslängd. Studier av askackumulering i dieselpartikelfilter är främst beroende av fälttester, vilket är både kostsamt och tidsintensivt. För att ta fram en mer ekonomisk testmetod, både avseende tid och kostnad, måste askackumuleringen i filtret kunna accelereras. Således genomfördes en litteraturstudie för att fastställa vilka testparametrar som främst påverkar askbildning och depositionsmönster i filter. I enlighet med den målsättningen har arbeten från ett flertal forskare utvärderats och sammanställts till ett designförslag för en testrigg för accelererande askackumulering. Den föreslagna testriggen medger kontroll av avgastemperatur och flöde, sotbildning, sotmorfologi, regenereringsintervall samt hur det askproducerande materialet introduceras. En brännare används för produktion av sot och aska, varefter avgaserna leds till filtret med hjälp av en fläkt. Fläkten motverkar tryckgradienten mellan in- och utloppet,vilket medger ett konstant gasflöde. För en mer precis temperaturkontroll kan en värmare placeras framför filtrets inlopp. Askproduktionsmetoder som kan testas är oljeinjektion ibrännarens flamma, oljeinjektion i gasflödet och slutligen oljeberikat bränsle. Genom att byta en brännare mot en partikelmatare kan riggen även fylla filtret med aska; artificiellt skapad eller alternativt samlad från faktiska filter. Utöver detta presenteras en serie frågeställningar som bör tas i beaktande för att möjliggöra bra specifikation av de ingående komponenterna och -karakterisering. Den föreslagna testriggen är designad utifrån ett modulkoncept, vilket innebär att komponenternas inbördes konfigurering kan varieras för att möjliggöra olika typerav tester och forskningsmål. / Aska

Askackumulering i dieselpartikelfilter är ett välkänt problem som resulterar i ett förhöjt mottryck och påverkad prestanda hos fordonet. Däremot ges sällan uppmärksamhet åt filtrets katalytiska aktivitet och hur det påverkas vid förekomst av avgasföroreningar. Syftet med denna studie är att undersöka effekten av aska på filtrets katalytisk aktivitet och dess förmåga att oxidera föroreningar som är skadliga för miljön och människors hälsa. Dessutom utvärderas askbeläggningsmetoden varpå filtren laboratoriskt åldras med olika typer, samt varierande mängder, av aska för att försöka simulera åldring i fält. Filtrens ytegenskaper karakteriserades genom analys med optisk mikroskopi, SEM-EDS och XRF. Den katalytiska aktivitet undersöktes i en SCAT-rigg, varpå oxidationstester av NOx och C3H8 utfördes. Det färska och fältåldrade jämfördes med de laboratorieåldrade filtren som dopats med 22 g/L respektive 47 g/L CaSO4 samt ett filter dopat med 79 g/L aska. Den katalytiska aktiviteten för laboratorieåldrade filtren liknande det färska filtret. Det fältåldrade filtret hade däremot låg katalytisk aktivitet för oxidation av NO och nästan helt deaktiverat för oxidation av C3H8. I det åldrade filtret och det laboratorieaskabelagda filtren visade EDS att elementen Ca och S hade väl matchade deponeringsregioner på filterkanalytan, vilket indikerade förekomst av CaSO4. Den mikroskopiska analysen indikerade också att båda proverna hade homogen fördelning av aska på filterkanalytan. Trots likheten i de fysiokemiska egenskaperna hos filterkanalytan hos det fältåldrade och laboratorieaskbelagda filtren hade de signfikant olika resultat vid test av katalytisk aktivitet. Deaktiveringen av det åldrade filtret kan ha orsakats av andra typer av åldringsmekanismer. Den valda metoden är inte adekvat för att efterlikna åldring i fält. Ytterligare studier krävs för att utvärdera metoden och effekterna av aska på den katalytiska aktiviteten / Accumulation of ash on the Catalytic Diesel Particulate Filter (CDPF) is a well-known problem that results in elevated back pressure and affected vehicle performance. However, attention is seldom paid to the catalytic performance of the filter, and how it is affected by impurities from the exhaust. The objective of this study is to address the effect of ash on the catalytic performance of CDPF to oxidise pollutants that are harmful to the environment and human health. In addition, evaluating the feasibility to laboratory age CDPFs with different loads and compositions using the dip-coating method to simulate field aged filters. The filter characterisation was analysed by Optical Microscopy, Scanning Electron Microscopy (SEM) with Electron dispersive X-ray Spectroscopy (EDS), and X-ray Fluorescence (XRF). The catalytic performance was investigated based on NOx and C3H8 oxidation tests in a Synthetic Catalyst Activity Test (SCAT) rig. A fresh and field aged filter was compared with laboratory aged filters prepared with coatings of 22 g/L and 47 g/L CaSO4, and 79 g/L ash , respectively. The catalytic activity to oxidise NO and C3H8 was unaffected by the ash deposits in the laboratory aged filters, showing similar activity as the fresh filter. While the field aged filter had low catalytic performance to convert NO and was almost completely deactivated for the oxidation of C3H8. EDS mapping for the field aged filter and the laboratory ash coated sample showed that the elements Ca and S were present and had well-matched regions of deposit, respectively, indicating that CaSO4 was present. The microscopic analysis also indicated that both samples had a homogeneous distribution of ash on the filter channel surface. Despite the similarity in the physicochemical properties of the filter channel surface(field aged filter and the laboratory ash coated sample) the catalytic activity had significantly different results. This study suggests that the deactivationof the field aged filter might be caused by other types of ageing mechanism. The laboratory ageing by dip-coating is seen as a non-applicable method to simulate field aged filters. Further studies are required to evaluate both the method and the effects of ash on the catalytic activity.

Yes / Implementation of an intelligent powertrain health management relies on robust prognostics modelling. However, prognostics capability is often limited due to unknown future operating conditions, which varies with duty cycles and individual driver behaviours. On the other hand, the growing availability of data pertaining to vehicle usage allows advanced modelling of usage patterns and driver behavious, bringing optimisation opportunities for powertrain operation and health management. This paper introduces a methodology for driving behaviour modelling, underpinned by Machine Learning classification algorithms, generating model-based predictive insight for intelligent powertrain health management strategies. Specifically, the aim is to learn the patterns of driving behaviour and predict characteristics for the short-term future operating conditions as a basis for enhanced control strategies to optimise energy efficiency and system reliability. A case study of an automotive emissions aftertreatment system is used to comprehensively demonstrate the proposed framework. The case study illustrates the approach for integrating predictive insight from machine learning deployed on real world trip behaviour data, in conjunction with a reliability-based model of the operational behaviour of a particulate filter, to propose an intelligent active regeneration control strategy for improved efficiency and reliability performance. The effectiveness of the proposed strategy was demonstrated on an industry standard model-in-the-loop set up with a representative sample of real-world vehicle driving data. / The authors acknowledge funding for the research presented in this article from Jaguar Land Rover under a research collaboration with the University of Bradford on “Intelligent Personalised Powertrain Healthcare”, and the Institute of Digital Engineering who have provided funding for proof of concept – the aiR-FORCE project.