Abstract
This work explores the mechanisms by which a post injection can reduce unburned hydrocarbon (UHC) emissions in heavy-duty diesel engines operating at low-temperature combustion conditions. Post injections, small, close-coupled injections of fuel after the main injection, have been shown to reduce UHC in the authors' previous work. In this work, we analyze optical data from laser-induced fluorescence of both CH2O and OH and use chemical reactor modeling to better understand the mechanism by which post injections reduce UHC emissions. The results indicate that post-injection efficacy, or the extent to which a post injection reduces UHC emissions, is a strong function of the cylinder pressure variation during the post injection. However, the data and analysis indicate that the pressure and temperature rise from the post injection combustion cannot solely explain the UHC reduction measured by both engine-out and optical diagnostics. The fluid-mechanic, thermal, and chemical interaction of the post injection with the main-injection mixture is a key part of UHC reduction; the starting action of the post jet and the subsequent entrainment of surrounding gases are likely both important processes in reducing UHC with a post injection.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 111-123 |
| Number of pages | 13 |
| Journal | Combustion and Flame |
| Volume | 170 |
| DOIs | |
| State | Published - Aug 1 2016 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy(all)
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Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine. / O'Connor, Jacqueline Antonia; Musculus, Mark P.B.; Pickett, Lyle M.
In: Combustion and Flame, Vol. 170, 01.08.2016, p. 111-123.Research output: Contribution to journal › Article
TY - JOUR
T1 - Effect of post injections on mixture preparation and unburned hydrocarbon emissions in a heavy-duty diesel engine
AU - O'Connor, Jacqueline Antonia
AU - Musculus, Mark P.B.
AU - Pickett, Lyle M.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - This work explores the mechanisms by which a post injection can reduce unburned hydrocarbon (UHC) emissions in heavy-duty diesel engines operating at low-temperature combustion conditions. Post injections, small, close-coupled injections of fuel after the main injection, have been shown to reduce UHC in the authors' previous work. In this work, we analyze optical data from laser-induced fluorescence of both CH2O and OH and use chemical reactor modeling to better understand the mechanism by which post injections reduce UHC emissions. The results indicate that post-injection efficacy, or the extent to which a post injection reduces UHC emissions, is a strong function of the cylinder pressure variation during the post injection. However, the data and analysis indicate that the pressure and temperature rise from the post injection combustion cannot solely explain the UHC reduction measured by both engine-out and optical diagnostics. The fluid-mechanic, thermal, and chemical interaction of the post injection with the main-injection mixture is a key part of UHC reduction; the starting action of the post jet and the subsequent entrainment of surrounding gases are likely both important processes in reducing UHC with a post injection.
AB - This work explores the mechanisms by which a post injection can reduce unburned hydrocarbon (UHC) emissions in heavy-duty diesel engines operating at low-temperature combustion conditions. Post injections, small, close-coupled injections of fuel after the main injection, have been shown to reduce UHC in the authors' previous work. In this work, we analyze optical data from laser-induced fluorescence of both CH2O and OH and use chemical reactor modeling to better understand the mechanism by which post injections reduce UHC emissions. The results indicate that post-injection efficacy, or the extent to which a post injection reduces UHC emissions, is a strong function of the cylinder pressure variation during the post injection. However, the data and analysis indicate that the pressure and temperature rise from the post injection combustion cannot solely explain the UHC reduction measured by both engine-out and optical diagnostics. The fluid-mechanic, thermal, and chemical interaction of the post injection with the main-injection mixture is a key part of UHC reduction; the starting action of the post jet and the subsequent entrainment of surrounding gases are likely both important processes in reducing UHC with a post injection.
UR - http://www.scopus.com/inward/record.url?scp=84971351743&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84971351743&partnerID=8YFLogxK
U2 - 10.1016/j.combustflame.2016.03.031
DO - 10.1016/j.combustflame.2016.03.031
M3 - Article
AN - SCOPUS:84971351743
VL - 170
SP - 111
EP - 123
JO - Combustion and Flame
JF - Combustion and Flame
SN - 0010-2180
ER -