| 1. |
- Khatri, Jayesh, 1993, et al.
(författare)
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Effect of relative humidity on water injection technique in downsized spark ignition engines
- 2021
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Ingår i: International Journal of Engine Research. - : SAGE Publications. - 1468-0874 .- 2041-3149. ; 22:7, s. 2119-2130
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Tidskriftsartikel (refereegranskat)abstract
- Combustion knock is a major barrier to achieving high thermal efficiency in spark ignition engines. Water injection was recently identified as a potential way of overcoming this barrier. To evaluate its general applicability, experiments were performed on a downsized three-cylinder spark ignition engine, varying the humidity of the intake air, the water injection timing, and the engine speed. The minimum quantity of injected water required to maintain a given load (and thus level of engine performance) was determined under each set of tested conditions. The knock-suppressing effects of water injection were found to be related to changes in the fuel–air mixture’s specific heat ratio (kappa) rather than evaporative cooling, and to therefore depend on the total quantity of water in the cylinder rather than the relative humidity per se. The total quantity of water in the cylinder was also shown to be a key determinant of advancement in combustion phasing and particulate emissions under various conditions.
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| 2. |
- Mu, Mingfei, 1990, et al.
(författare)
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Experimental study on the flow field of particles deposited on a gasoline particulate filter
- 2019
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 12:14
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Tidskriftsartikel (refereegranskat)abstract
- The abatement of particulate matter in gasoline vehicle exhaust has prompted the development of gasoline particulate filters (GPFs). The spatial distribution of the deposited particles inside a GPF has profound implications for its regeneration behavior, ash-induced aging, and multiscale modeling efforts. The connection cones will affect the flow into the monolith and the package structure needed to meet the system space requirements. In this paper, nonuniform rational B-splines (NURBSs) were applied to the cone design to optimize the flow uniformity and particle distribution inside a gasoline particulate filter. NURBS and conventional cones were manufactured using 3D printing, and the velocity profiles and pressure drops were measured under the loading of synthetic particles. The results shows that the cone shape will influence the pressure drop and the velocity profile, which is evaluated as the uniformity index. The test results indicate that better performance is achieved when using the NURBS cone, especially at low particle loads. The results also show that the cone shape (which determines the velocity profile) influences the particle deposition distribution, although the apparent pressure drops are similar. These results are important for exhaust aftertreatment system (EATS) design and optimization, where the NURBS cone can improve flow uniformity, which causes better particle deposition distribution and lower pressure drop.
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| 3. |
- Sharma, Nikhil, 1986, et al.
(författare)
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Characterization from Diesel and Renewable Fuel Engine Exhaust: Particulate Size/Mass Distributions and Optical Properties
- 2023
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Ingår i: Aerosol Science and Engineering. - : Springer Science and Business Media LLC. - 2510-375X .- 2510-3768. ; 7, s. 182-191
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Tidskriftsartikel (refereegranskat)abstract
- Combustion of fossil fuel produces emissions and is one of the major environmental problems leading to climate change. Diesel engines are highly efficient but produce particulate emissions. These particulate emissions are considered dangerous to human health because inhaling particulates may cause respiratory and heart disease. Substituting fossil diesel fuel with renewable diesel fuel and using diesel particulate filters is one possibility to meet stringent legislative requirements. With this motivation, the present experimental investigation aimed to evaluate the particle size distribution (PSD), optical properties of particulate matter (PM) emitted, and the outcome of using an after-treatment system comprising of a diesel particle filter (DPF). This investigation aimed to make a comparative analysis of particulate emission upstream and downstream of the DPF with and without ultraviolet (UV) light (405 nm and 781 nm wavelength) turned on/off. Experiments were performed at (a) engine idle with a torque of 6 Nm at 750 rpm, IMEP of 1.35 bar and power of 0.5 kW, (b) engine at part load with a torque of 32 Nm at 1200 rpm, IMEP of 8.5 bar and power of 4.5 kW. Diesel engine was operated on two fuels (a) Diesel and (b) EHR7. Results showed that as and when UV light was turned on, a distinct nucleation mode that dominated the number concentration for both test fuels were observed. Downstream of the filter had relatively higher AAE values which show the contribution to climate change. Present experimental research is important for renewable fuel industries, industrial innovation's future, and the exhaust gas after-treatment system (EATS) community. The results contribute to knowledge for occupational exposure, human health, and the environment.
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| 4. |
- Sharma, Nikhil, 1986, et al.
(författare)
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Morphological characterization of soot from a compression ignition engine fueled with diesel and an oxygenated fuel
- 2023
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Ingår i: International Journal of Engine Research. - : SAGE Publications. - 1468-0874 .- 2041-3149. ; 24:3, s. 1063-1076
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Tidskriftsartikel (refereegranskat)abstract
- Compression ignition (CI) engines are highly efficient and are therefore often the first choice in application of heavy machinery and heavy duty vehicles. However, diesel engines are known to emit soot and oxides of nitrogen (NOx) emission. Replacing fossil diesel fuel with renewable fuel is one possibility to reduce emissions and to meet legislative requirements. In this experimental work, an oxygenated fuel blend was investigated for soot morphology and results were compared with fossil diesel fuel without oxygenates. Soot was sampled at a medium load case in a light duty single cylinder research engine and samples were analyzed with a transmission electron microscope (TEM). Furthermore, combustion characteristics and particle number (PN) emissions were compared for both fuels. The primary particle diameter (Dp), fringe length (L), fringe separation (S), and tortuosity (T) were also discussed in terms of soot nanostructure. The particle size distribution (PSD) showed a reduction in PN over for the renewable fuel blend compared to diesel. This PN reduction was from 107 to 106 (one order magnitude lower). The maximum Dp from morphological analysis of diesel fuel and renewable fuel was 69.93 and 66.36 nm respectively. Size range of fringe separation (S) was nearly identical for both fuels. Diesel fuel has marginally higher fringe separation, fringe length, and tortuosity. This investigation is valuable for fuel industries which are continuously upgrading renewable and oxygenated fuels to meet stringent emission norms.
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| 5. |
- Singh, Akhilendra Pratap, et al.
(författare)
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Introduction to Advanced Combustion Techniques and Engine Technologies for Automotive Sector
- 2020
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Ingår i: Energy, Environment, and Sustainability. - Singapore : Springer Singapore. - 2522-8374 .- 2522-8366. ; , s. 3-6
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- To resolve the transportation sector issues such as rapidly increasing petroleum consumption and stringent emission norms for vehicles, researchers have proposed three solution strategies namely advanced combustion techniques, after-treatment systems and alternative fuels. This book covers all three aspects for automotive sector. A dedicated section of this book is based on methanol, which discusses about the methanol utilization strategies in vehicles, especially in two wheelers. Second section of this book is based on advanced combustion techniques, which includes gasoline compression ignition (GCI), gasoline direct injection (GDI), and spark assisted compression ignition (SACI). Fourth section is based on emissions and after treatments systems. Last section of this book includes two different aspects. First is the vehicle lightweighting and second is the development of UAVs for defence applications. Overall this book emphasizes on different techniques, which can improve engine efficiency and reduce harmful emissions for a sustainable transport system.
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