Modeling HCCI using CFD and Detailed Chemistry with Experimental Validation and a Focus on CO Emissions Page: 3 of 8
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
Modeling HCCI using CFD and Detailed Chemistry with Experimental Validation and a Focus on CO
Emissions
Randy Hessel and Dave Foster
University of Wisconsin-Madison, Engine Research Center
Salvador Aceves, Daniel Flowers and Bill Pitz
Lawrence Livermore National Laboratory
John Dec and Magnus Sjoberg
Sandia National Laboratory
Aristotelis Babajimopoulos
University of Michigan, Automotive Laboratory
Multi-zone CFD simulations with detailed kinetics were used to model engine experiments performed on a
diesel engine that was converted for single cylinder, HCCI operation, here using iso-octane as the fuel. The
modeling goals were to validate the method (multi-zone combustion modeling) and the reaction mechanism
(LLNL 857 species iso-octane), both of which performed very well. The purpose of this paper is to
document the validation findings and to set the ground work for further analysis of the results by first
looking at CO emissions characteristics with varying equivalence ratio.
Experimental SetupThr1d ng in
Ov r adlmel5.88 mm
(0.2314 in)
5.23 mm
r(0.206 in)0.305 mm
(0.0120 in)
16.47mm
r(0.648 in).102mm
(4.02 in)Experiments were carried out on a Sandia National
Laboratories research engine, which is based on a
Cummins B-series diesel engine, a typical medium-
duty diesel engine with a displacement of 0.98
liters/cylinder. Figure 1 (top) shows a schematic of
the engine, which has been converted for single
cylinder HCCI operation. The engine specifications
are listed in Table 1 [1].
Figure 1 (bottom) is a schematic of the combustion
chamber and includes representations of the liner,
head (no valves), piston with a shallow dish, the top
ring and ring groove. The air compressor (figure 1
] top) was used to boost the intake charge (table 1) so
that the currently used 13.8 compression ratio piston
would be representative of previous work done on
this engine, but performed naturally aspirated, with
a 18:1 compression ratio piston. Intake temperature
(table 1) was varied with the Main Air Heater
(figure 1) to maintain the 50% heat release point at
top dead center as equivalence ratio was varied
from 0.08 to 0.28 in steps of 0.02. Iso-octane was
injected into the Fuel Vaporizer (figure 1 top, top-
center) to provide a pre-mixed charge to the
cylinder.Figure 1. Schematics of engine (top) and
combustion chamber (bottom).
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Hessel, R.; Foster, D.; Aceves, S.; Flowers, D.; Pitz, B.; Dec, J. et al. Modeling HCCI using CFD and Detailed Chemistry with Experimental Validation and a Focus on CO Emissions, article, April 23, 2007; Livermore, California. (https://digital.library.unt.edu/ark:/67531/metadc889530/m1/3/: accessed April 20, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.