Large eddy simulation of dual-fuel combustion under ICE conditions
Summary, in English
First, the ESF approach with a novel modified method is proposed, implemented, and evaluated. Results show that the modified ESF method removes the numerical error in the element mass conservation and shows capability in predicting both premixed and non-premixed flames relevant to dual-fuel combustion. Second, LES of n-heptane single-fuel and n-heptane/methanol dual-fuel combustion is carried out and validated against ECN Spray-H experiments. A good agreement is obtained in terms of flow, combustion, and emissions characteristics.
Finally, a parameter study is performed to investigate the effects of the dual-fuel strategies, including the primary fuel concentration, the ambient temperature, and the pilot fuel injection timing. It is concluded that: 1) The ambient methanol is found to have an effect of suppressing the two-stage ignition and heat release of n-heptane, this is more significant under high ambient methanol concentration conditions. 2) The effects of methanol on the n-heptane ignition and NOx formation are strongly dependent on the ambient temperatures. The retardation of the n-heptane high temperature ignition is more remarkable under low ambient temperatures. The NOx and soot in the dual-fuel case is lower than that of the single-fuel case in moderately high initial temperatures, while an opposite trend is observed in higher temperatures. 3) A late injection may lead to an overlap of the ambient methanol auto-ignition and the delivery of n-heptane. This overlap results in high soot and NOx formation.
Division of Fluid Mechanics, Department of Energy Sciences, Lund Institute of Technology, Lund University
- Fluid Mechanics and Acoustics
- Energy Engineering
- Aerospace Engineering
- Turbulent combustion
- transported probability density function
- ISSN: 0282-1990
- ISBN: 978-91-7895-881-8
- ISBN: 978-91-7895-882-5
30 August 2021
Lecture hall KC:Rudolf, Kemicentrum, Naturvetarvägen 14, Faculty of Engineering LTH, Lund University, Lund.
- Ville Vuorinen (Ass. Prof.)