Development of a Simulation based Powertrain Design Framework for Evaluation of Transient Soot Emissions from Diesel Engine Vehicles.

This dissertation presents the development of a modeling and simulation framework for diesel engine vehicles to enable soot emissions as a constraint in powertrain design and control. To this end, numerically efficient models for predicting temporallyresolved transient soot emissions are identified in the form of a third-order dual-input single-output (DISO) Volterra series from transient soot data recorded by integrating real-time (RT) vehicle level models in Engine-in-the-loop (EIL) experiments. It is shown that the prediction accuracy of transient soot significantly improves over the steady-state maps, while the model remains computationally efficient for systemslevel work. The evaluation of powertrain design also requires a systematic procedure for dealing with the issue that drivers potentially adapt their driving styles to a given design. In order to evaluate the implications of different powertrain design changes on transient soot production it is essential to compare these design changes on a consistent basis. This problem is explored in the context of longitudinal motion of a vehicle following a standard drive-cycle repeatedly. This dissertation develops a proportional-derivative (PD) type iterative learning based algorithm to synthesize driver actuator inputs that seek to minimize soot emissions using the Volterra series based transient soot models. The solution is compared to the one obtained using linear programming. Results show that about 19% reduction in total soot can be achieved for the powertrain design considered in about 40 iterations. The two contributions of this dissertation: development of computationally efficient system level transient soot models and the synthesis of driver inputs via iterative learning for reducing soot, both contribute to improving the art of modeling and simulation for diesel powertrain design and control.Ph.D.Mechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/86386/1/ahlawatr_1.pd

Particle size distribution from municipal solid waste burning over National Capital Territory, India

Proceeding paper, presented at the 5th International Electronic Conference on Atmospheric Sciences, 16–31 July 2022. Emission of particulate matter (PM) of different sizes from Municipal Solid Waste (MSW) burning may have an impact on air quality and human health of the National Capital Territory (NCT) of India, particularly during winter months. MSW samples were collected from three sanitary landfill sites in the NCT Delhi. Experiments were performed to mimic real world burning during different stages of sample combustion (ignition, flaming smoldering, smoldering and pyrolysis). We determined the emission factor for the number and mass concentration of particles of different sizes, ranging from 0.34 to 9.05 µm, for MSW burning. Present results confirm the assumption that MSW burning emits the maximum number concentration (No/cm3) of particles (90%) in the range < 1.0 µm, or fine-mode aerosol

Non-methane volatile organic compounds emitted from domestic fuels in Delhi: Emission factors and total city-wide emissions

In controlled laboratory conditions, 62 samples of domestic fuels collected from 56 grids of Delhi were burnt to quantify the emissions of 23 non-methane volatile organic compounds (NMVOCs), i.e., alkanes (11), alkenes (6), alkynes (1) and aromatic compounds (5). The domestic fuels used for residential activities were comprised of 20 unique types of fuel woods, 3 species of crop residue, dung cakes and coal. These fuels are primarily used for cooking and water/space heating during winters. The current study reports the total emission budget of NMVOCs from domestic burning over Delhi. Furthermore, this study also compares the differences in EFs of NMVOCs which are calculated for different burning cycles and sample collection methods. The EFs of NMVOCs calculated from the samples collected during the flaming stage using canisters were analysed for 23 NMVOCs and then compared with same species emitted from complete burning cycle. In addition to this, 10 consumption and emission hotspot grids were also identified in Delhi; based on the ground survey and laboratory simulated results. The total annual usage of domestic fuels for the year 2019 was found to be 0.415 Mt/yr (million tonnes) in Delhi. 12.01 Gg/yr of annual NMVOC emissions was calculated from domestic fuel burning in which the emissions from dung cake and fuel wood dominated with 6.6 Gg/yr and 5.4 Gg/yr, respectively. The EFs of NMVOCs calculated using canister and online collection method differ significantly from each other. The flaming stage presented enhanced emissions compared to the complete burning cycle by ~7 times which suggests that the method of data analysis and the period of sample collection play a pivotal role in the preparation of an emission inventory and estimating the budget

Emissions of non-methane volatile organic compounds from combustion of domestic fuels in Delhi, India

Twenty-nine different fuel types used in residential dwellings in northern India were collected from across Delhi (76 samples in total). Emission factors of a wide range of non-methane volatile organic compounds (NMVOCs) (192 compounds in total) were measured during controlled burning experiments using dualchannel gas chromatography with flame ionisation detection (DC-GC-FID), two-dimensional gas chromatography (GC×GC-FID), proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and solid-phase extraction two-dimensional gas chromatography with time-offlight mass spectrometry (SPE-GC×GC-ToF-MS). On average, 94% speciation of total measured NMVOC emissions was achieved across all fuel types. The largest contributors to emissions from most fuel types were small non-aromatic oxygenated species, phenolics and furanics. The emission factors (in g kg-1) for total gas-phase NMVOCs were fuelwood (18.7, 4.3-96.7), cow dung cake (62.0, 35.3-83.0), crop residue (37.9, 8.9-73.8), charcoal (5.4, 2.4-7.9), sawdust (72.4, 28.6-115.5), municipal solid waste (87.3, 56.6- 119.1) and liquefied petroleum gas (5.7, 1.9-9.8). The emission factors measured in this study allow for better characterisation, evaluation and understanding of the air quality impacts of residential solid-fuel combustion in India

Emissions of intermediate-volatility and semi-volatile organic compounds from domestic fuels used in Delhi, India

Biomass burning emits significant quantities of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) in a complex mixture, probably containing many thousands of chemical species. These components are significantly more toxic and have poorly understood chemistry compared to volatile organic compounds routinely quantified in ambient air; however, analysis of I/SVOCs presents a difficult analytical challenge. The gases and particles emitted during the test combustion of a range of domestic solid fuels collected from across Delhi were sampled and analysed. Organic aerosol was collected onto Teflon (PTFE) filters, and residual low-volatility gases were adsorbed to the surface of solid-phase extraction (SPE) discs. A new method relying on accelerated solvent extraction (ASE) coupled to comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-ToF-MS) was developed. This highly sensitive and powerful analytical technique enabled over 3000 peaks from I/SVOC species with unique mass spectra to be detected. A total of 15 %-100% of gas-phase emissions and 7 %-100% of particle-phase emissions were characterised. The method was analysed for suitability to make quantitative measurements of I/SVOCs using SPE discs. Analysis of SPE discs indicated phenolic and furanic compounds were important for gas-phase I/SVOC emissions and levoglucosan to the aerosol phase. Gas- and particle-phase emission factors for 21 polycyclic aromatic hydrocarbons (PAHs) were derived, including 16 compounds listed by the US EPA as priority pollutants. Gas-phase emissions were dominated by smaller PAHs. The new emission factors were measured (mg kg-1) for PAHs from combustion of cow dung cake (615), municipal solid waste (1022), crop residue (747), sawdust (1236), fuelwood (247), charcoal (151) and liquefied petroleum gas (56). The results of this study indicate that cow dung cake and municipal solid waste burning are likely to be significant PAH sources, and further study is required to quantify their impact alongside emissions from fuelwood burning

Phytomitogen induced changes in levels of inositol phosphates in the bovine lymphocytes

173-177The changes in levels of inositol phosphates and phosphoinositides were studied in the bovine lymphocytes, in response to phytomitogens (lectins)-concanavalinA (conA) and phytohaemagglutinin (PHA). Addition of conA and PHA resulted in a rapid increase in the cpm of total inositol phosphates (from 8599 ± 100 cpm/2 10⁶ cells to 11228 ± 126 cpm/2 10⁶ and 9758 ± 100 cpm/2 10⁶ cells, respectively) at 1 min after mitogen stimulation. There was a concomitant decrease in the phosphatidylinositol levels at 1 min, which continued up to 5 min. At 1 min of stimulation, inositol diphosphate fraction exhibited maximum increase, as compared to inositol mono- and triphosphates, suggesting that it contributed the most towards the overall increase in the total inositol phosphates levels. Results suggest that bovine lymphocytes respond to phytomitogens with a rapid turnover of phosphoinositides

Elemental Variation and Health Risk Assessment of PM2.5 at Delhi during North-East Monsoon and South-West Monsoon

This study elucidates the variation of PM2.5 concentrations in Delhi during the north-east monsoon (NEM) and the south-west monsoon (SWM) period of 2014&ndash;2019. The average concentrations of PM2.5 were 113 &plusmn; 48 &micro;g/m3 and 50 &plusmn; 19 &micro;g/m3 during NEM and SWM, respectively. Further, the elemental composition of PM2.5 was analyzed using wavelength dispersive X-ray Fluorescence (WD-XRF). During NEM, it was observed that the Na, Cl and S dominating over the region, whereas Na, S, Al, dominated during the SWM season. Backward trajectories analysis suggested the long-range transportation of air mass from the Sahara Desert (SD), Arabian Sea (AS), and Bay of Bengal (BOB) for both the seasons (NEM and SWM), thus significantly affecting the loading of mass concentration of PM2.5 at the study site of Delhi. We also evaluated the hazard quotient (HQ) of elements present in PM2.5 over Delhi during this period