An Investigation of the Replacement of E10, E85, and Methane with
Gasoline in Reactivity Controlled Compression Ignition Combustion: A Comparison
of Alternative Fuels Using Reactivity Controlled Compression Ignition
The Reactivity Controlled Compression Ignition (RCCI) strategy is a novel
Low-Temperature Combustion (LTC) strategy that is used to minimize nitrogen
oxides (NOX) and soot emissions to near zero. Methane and ethanol
blends are the most conventional alternatives to gasoline used in the RCCI
strategy. In this paper, a three-dimensional Computational Fluid Dynamics
(3D-CFD) model was developed and validated against the experimental data at the
load of 6.5 bar Indicated Mean Effective Pressure (IMEP) and 1300 rpm. E10, E85,
and methane were replaced with gasoline to investigate their effects on
emissions and performance. In order to make a fair comparison between cases,
combustion phasing (CA50) and cylinder energy and boundary conditions were
considered constant. Conventional Diesel Combustion (CDC) was also investigated
with the constant cylinder energy to make a comparison between all RCCI cases
and CDC. Adding ethanol in gasoline showed that it can increase the gross
thermal efficiency (GTE) up to 1.3%, but at the expense of higher fuel
consumption. Ethanol fraction resulted in better fuel oxidization, and lower
unburned hydrocarbon (UHC) and carbon monoxide (CO). The methane/diesel RCCI
case had lower GTE compared to other RCCI cases, but it still showed higher GTE
than CDC. One of the main drawbacks of the methane/diesel RCCI case was the high
levels of UHC and CO, but fuel consumption was lower than gasoline/diesel RCCI.
From the emissions standpoint, all RCCI cases managed to meet EURO6 and EPA2010
emission mandates for NOX, soot, and CO. However, it is impossible
for the CDC strategy to meet these regulations without adopting aftertreatments.
The CDC strategy had about 98% of the total produced NOX and soot in
all cases. On the other hand, 63% and 51% of the total produced UHC and CO
belonged to the methane/diesel case. From the global warming concerns and carbon
dioxide (CO2) perspective, the CDC case produced 547.1 g/kW-h
CO2 while the methane case produced 350.9 g/kW-h CO2.
Other cases (gasoline, E10, and E85) showed middle levels of CO2 by
about 460 g/kW-h.
Citation: Shirvani, S., Shirvani, S., and Shamekhi, A., "An Investigation of the Replacement of E10, E85, and Methane with Gasoline in Reactivity Controlled Compression Ignition Combustion: A Comparison of Alternative Fuels Using Reactivity Controlled Compression Ignition Strategy," SAE Technical Paper 2020-01-5061, 2020, https://doi.org/10.4271/2020-01-5061. Download Citation
Sasan Shirvani, Saeid Shirvani, Amir H. Shamekhi
KN Toosi University of Technology
Automotive Technical Papers
Computational fluid dynamics
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