The Oxidation Potential Number: An Index to Evaluate Inherent Soot Reduction in D.I. Diesel Spray Plumes

Graziano, Barbara; Heuser, Benedikt; Kremer, Florian; Pischinger, Stefan; Rohs, Hans

doi:10.4271/2015-01-1934

Cited by 10 publications

(6 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Further detail on the algorithm can be found in Senecal. 35 The oxidation potential number (OPN) of Graziano et al 36 was chosen as merit function since good air utilization (AU) at rated power is essential for an efficient combustion system throughout the whole load and speed range. [37][38][39] This characteristic number relates the zones of lean mixture within the combustions chamber to the rich and overly lean zones (see equation 2).…”

Section: Computational Optimizationmentioning

confidence: 99%

Combustion system optimization for dimethyl ether using a genetic algorithm

Zubel

Ottenwälder

Heuser

et al. 2019

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

Dimethyl ether is a gaseous fuel which can easily be liquefied under moderate pressures. Its high reactivity makes it suitable for combustion in a compression ignition engine, and due to the high oxygen content, its combustion is virtually free of soot. The high oxygen content and low density of dimethyl ether lead to a lower volumetric heating value compared to Diesel fuel. Therefore, the hydraulic flow rates of the injectors have to be increased with larger nozzle holes. The influence of larger nozzle holes on the dimethyl ether spray formation and ignition are presented in this article. Experimental investigations were conducted at a constant-pressure vessel with optical access and with a single-cylinder research engine. Subsequently, a numerical optimization of the piston bowl and injector nozzle has been carried out. A very fast air/fuel mixture formation with dimethyl ether was observed, which leads to a lean combustion with small nozzle diameters. With increasing nozzle diameters, the combustion moves toward stoichiometric conditions and with very large diameters to rich combustion conditions. The ignition delay for small diameters is mostly dominated by the lean mixture, and for large diameters, the ignition delay is strongly influenced by cooling effects. For the optimization, the oxidation potential number was maximized, which proved suitable to simultaneously increase efficiency and reduce emissions. A conventional ω-shaped bowl and a step bowl have been optimized, and large bowl diameters were found to be beneficial for dimethyl ether combustion. Furthermore, nozzle diameters around 150 µm showed the most promising results. Compared to the dimethyl ether reference, the simulations with the optimized ω-shaped bowl showed a power increase of 2.7%. Experimentally, the optimized ω-shaped bowl in combination with the reference injector showed an efficiency increase by more than 1% at 2000 r/min full load compared to the dimethyl ether reference.

show abstract

Section: Computational Optimizationmentioning

confidence: 99%

Combustion system optimization for dimethyl ether using a genetic algorithm

Zubel

Ottenwälder

Heuser

et al. 2019

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, changing the molecular structure of the fuel will cause significant changes in the vaporization and emission behavior. Hence, descriptors that rate the mixing behavior or the intrinsic soot formation tendency must be developed …”

Section: Biofuels—status and Requirementsmentioning

confidence: 99%

“…Hence,descriptors that rate the mixing behavior or the intrinsic soot formation tendency must be developed. [68] Derived cetane numbers (DCNs) of selected biofuel structures that are in the focus of this Review have recently been evaluated by Sudholt et al [69] Ther esults are shown in Figure 1i nc omparison to n-heptane.T he examples are all based on five-membered oxygen-containing heterocycles, ranging from heteroaromatic furans to fully saturated tetrahydrofuran derivatives.I ti si mportant to note that the oxygen-containing furanic structures do not suffer from the severe limitations related to soot emission as purely hydrocarbon-based aromatic compounds.S tructural parameters such as bond dissociation energies (BDEs) and initial reactions were considered, and experiments were conducted in aconstant volume chamber to determine the ignition delay times and resulting DCNs. [69] Figure 1also shows the required minimum CN values for the EU and the USA, and all fuels with DCNs close to or above these limits can be used in ac ompression-ignition engine.C onversely,f uels with al ow DCN are highly knockresistant and can be used in spark-ignition engines;f or comparison, the DCN corresponding to aRON 90 fuel is also indicated.…”

Section: Biofuels-status and Requirementsmentioning

confidence: 99%

Advanced Biofuels and Beyond: Chemistry Solutions for Propulsion and Production

et al. 2017

Self Cite

View full text Add to dashboard Cite

Sustainably produced biofuels, especially when they are derived from lignocellulosic biomass, are being discussed intensively for future ground transportation. Traditionally, research activities focus on the synthesis process, while leaving their combustion properties to be evaluated by a different community. This Review adopts an integrative view of engine combustion and fuel synthesis, focusing on chemical aspects as the common denominator. It will be demonstrated that a fundamental understanding of the combustion process can be instrumental to derive design criteria for the molecular structure of fuel candidates, which can then be targets for the analysis of synthetic pathways and the development of catalytic production routes. With such an integrative approach to fuel design, it will be possible to improve systematically the entire system, spanning biomass feedstock, conversion process, fuel, engine, and pollutants with a view to improve the carbon footprint, increase efficiency, and reduce emissions.

show abstract

“…So verursacht etwa eine Veränderung der Molekülstruktur des Kraftstoffs tiefgreifende Veränderungen im Verdampfungs‐ und Emissionsverhalten. Somit ist die Entwicklung von Deskriptoren zur Bewertung des Mischungsverhaltens oder der intrinsischen Rußbildungstendenz nötig …”

Section: Biokraftstoffe – Forschungsstand Und Anforderungenunclassified

Synthese, motorische Verbrennung, Emissionen: Chemische Aspekte des Kraftstoffdesigns

et al. 2017

Self Cite

View full text Add to dashboard Cite

Nachhaltig produzierte Biokraftstoffe, die auf Basis von Lignozellulose zugänglich sind, werden in Energieszenarien für Mobilität und Transport der Zukunft intensiv diskutiert. Traditionell konzentrieren sich die Forschungsaktivitäten in den Naturwissenschaften dabei auf den Syntheseprozess, während die anschließende Bewertung der Verbrennungseigenschaften anderen Forschungsgebieten überlassen wird. Dieser Aufsatz verfolgt mit der gemeinsamen Betrachtung der motorischen Verbrennung und der Kraftstoffsynthese einen integrativen Ansatz, bei dem die chemischen Aspekte im Vordergrund stehen. Dabei wird deutlich, dass das fundamentale Verständnis des Verbrennungsvorgangs maßgeblich dazu beitragen kann, Designkriterien für die Molekülstruktur möglicher Kraftstoffkandidaten abzuleiten, um so Ziele für die Analyse von Synthesewegen und die Entwicklung katalytischer Produktionswege zu definieren. Dieser integrative Ansatz des “Kraftstoffdesigns” umfasst die gesamte Kette der Energiekonversion ausgehend vom Rohstoff über Herstellungsprozess, Kraftstoff und Motor bis hin zur Schadstoffemission. Dies ermöglicht eine systematische Optimierung des Gesamtsystems mit dem Ziel, die Kohlenstoffbilanz zu verbessern, die Effizienz zu erhöhen und die Emissionen zu verringern.

show abstract

The Oxidation Potential Number: An Index to Evaluate Inherent Soot Reduction in D.I. Diesel Spray Plumes

Cited by 10 publications

References 25 publications

Combustion system optimization for dimethyl ether using a genetic algorithm

Combustion system optimization for dimethyl ether using a genetic algorithm

Advanced Biofuels and Beyond: Chemistry Solutions for Propulsion and Production

Synthese, motorische Verbrennung, Emissionen: Chemische Aspekte des Kraftstoffdesigns

Contact Info

Product

Resources

About