Investigation of Species from Negative Valve Overlap Reforming Using a Stochastic Reactor Model

Seamus Kane, Xuesong Li, Benjamin Wolk, Isaac Ekoto, William Northrop

Research output: Contribution to journalConference article

2 Citations (Scopus)

Abstract

Fuel reforming during a Negative Valve Overlap (NVO) period is an effective approach to control Low Temperature Gasoline Combustion (LTGC) ignition. Previous work has shown through experiments that primary reference fuels reform easily and produce several species that drastically affect ignition characteristics. However, our previous research has been unable to accurately predict measured reformate composition at the end of the NVO period using simple single-zone models. In this work, we use a stochastic reactor model (SRM) closed cycle engine simulation to predict reformate composition accounting for in-cylinder temperature and mixture stratification. The SRM model is less computationally intensive than CFD simulations while still allowing the use of large chemical mechanisms to predict intermediate species formation rates. By comparing model results with experimental speciation data from a single-cylinder engine, the presented work provides insight into the thermodynamic and kinetic processes that occur during in-cylinder fuel reformation. Three single-component fuels (iso-octane, n-heptane and ethanol) were modeled as a function of assumed thermal stratification. Across thermal stratification levels, the modeled reformate concentrations match well with measured values though they are very sensitive to initial conditions. The relationship between thermal stratification and resulting reformed species provides insight into the effect of non-homogeneity on products and illustrates the value of SRM over homogeneous reactor models to inexpensively predict in-cylinder processes.

Original languageEnglish (US)
JournalSAE Technical Papers
Volume2017-March
Issue numberMarch
DOIs
StatePublished - Mar 28 2017
EventSAE World Congress Experience, WCX 2017 - Detroit, United States
Duration: Apr 4 2017Apr 6 2017

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Reforming reactions
Engine cylinders
Thermal stratification
Ignition
Heptane
Chemical analysis
Gasoline
Computational fluid dynamics
Ethanol
Thermodynamics
Engines
Temperature
Kinetics
Experiments

Cite this

Investigation of Species from Negative Valve Overlap Reforming Using a Stochastic Reactor Model. / Kane, Seamus; Li, Xuesong; Wolk, Benjamin; Ekoto, Isaac; Northrop, William.

In: SAE Technical Papers, Vol. 2017-March, No. March, 28.03.2017.

Research output: Contribution to journalConference article

Kane, Seamus ; Li, Xuesong ; Wolk, Benjamin ; Ekoto, Isaac ; Northrop, William. / Investigation of Species from Negative Valve Overlap Reforming Using a Stochastic Reactor Model. In: SAE Technical Papers. 2017 ; Vol. 2017-March, No. March.
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