Reacting Boundary Layers in Homogeneous Charge Compression Ignition (HCCI) Engine
(2001) SAE World Congress, 2001 p.1086-1098- Abstract
- An experimental and computational study of the nearwall
combustion in a Homogeneous Charge
Compression Ignition (HCCI) engine has been conducted
by applying laser based diagnostic techniques in
combination with numerical modeling. Our major intent
was to characterize the combustion in the velocity- and
thermal boundary layers. The progress of the combustion
was studied by using fuel tracer LIF, the result of which
was compared with LDA measurements of the velocity
boundary layer along with numerical simulations of the
reacting boundary layer.
Time resolved images of the PLIF signal were taken and
ensemble averaged images were... (More) - An experimental and computational study of the nearwall
combustion in a Homogeneous Charge
Compression Ignition (HCCI) engine has been conducted
by applying laser based diagnostic techniques in
combination with numerical modeling. Our major intent
was to characterize the combustion in the velocity- and
thermal boundary layers. The progress of the combustion
was studied by using fuel tracer LIF, the result of which
was compared with LDA measurements of the velocity
boundary layer along with numerical simulations of the
reacting boundary layer.
Time resolved images of the PLIF signal were taken and
ensemble averaged images were calculated. In the fuel
tracer LIF experiments, acetone was seeded into the fuel
as a tracer. It is clear from the experiments that a proper
set of backgrounds and laser profiles are necessary to
resolve the near-wall concentration profiles, even at a
qualitative level. Partial resolution of the velocity
boundary layer was enabled by using a slightly inclined
LDA probe operated in back-scatter mode. During these
conditions, it was possible to acquire velocity data within
0.2 mm from the wall. A one-dimensional model of the
flow field was devised to make the connection between
the thermal and the velocity boundary layer.
The investigations suggest that wall interaction is not the
responsible mechanism for the rather high emissions of
unburned hydrocarbons from HCCI engines. It is
believed that the delayed oxidation, indicated by the fuel
tracer LIF experiments and numerical simulations, is due
to the thermal boundary layer. From the data at hand, it
is concluded that the thermal boundary layer is on the
order of 1 mm thick. In this boundary layer the reactions
are delayed but not quenched. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1041088
- author
- Hultqvist, Anders LU ; Engdar, Ulf LU ; Johansson, Bengt LU and Klingmann, Jens LU
- organization
- publishing date
- 2001
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- SAE Transactions
- pages
- 1086 - 1098
- publisher
- SAE
- conference name
- SAE World Congress, 2001
- conference location
- Detroit, MI, United States
- conference dates
- 2001-03-05 - 2001-03-08
- language
- English
- LU publication?
- yes
- id
- 2754f4b0-6484-4457-b65e-246464a80778 (old id 1041088)
- alternative location
- http://www.sae.org/technical/papers/2001-01-1032
- date added to LUP
- 2016-04-04 11:31:16
- date last changed
- 2018-11-21 21:05:22
@inproceedings{2754f4b0-6484-4457-b65e-246464a80778,
abstract = {{An experimental and computational study of the nearwall<br/><br>
combustion in a Homogeneous Charge<br/><br>
Compression Ignition (HCCI) engine has been conducted<br/><br>
by applying laser based diagnostic techniques in<br/><br>
combination with numerical modeling. Our major intent<br/><br>
was to characterize the combustion in the velocity- and<br/><br>
thermal boundary layers. The progress of the combustion<br/><br>
was studied by using fuel tracer LIF, the result of which<br/><br>
was compared with LDA measurements of the velocity<br/><br>
boundary layer along with numerical simulations of the<br/><br>
reacting boundary layer.<br/><br>
Time resolved images of the PLIF signal were taken and<br/><br>
ensemble averaged images were calculated. In the fuel<br/><br>
tracer LIF experiments, acetone was seeded into the fuel<br/><br>
as a tracer. It is clear from the experiments that a proper<br/><br>
set of backgrounds and laser profiles are necessary to<br/><br>
resolve the near-wall concentration profiles, even at a<br/><br>
qualitative level. Partial resolution of the velocity<br/><br>
boundary layer was enabled by using a slightly inclined<br/><br>
LDA probe operated in back-scatter mode. During these<br/><br>
conditions, it was possible to acquire velocity data within<br/><br>
0.2 mm from the wall. A one-dimensional model of the<br/><br>
flow field was devised to make the connection between<br/><br>
the thermal and the velocity boundary layer.<br/><br>
The investigations suggest that wall interaction is not the<br/><br>
responsible mechanism for the rather high emissions of<br/><br>
unburned hydrocarbons from HCCI engines. It is<br/><br>
believed that the delayed oxidation, indicated by the fuel<br/><br>
tracer LIF experiments and numerical simulations, is due<br/><br>
to the thermal boundary layer. From the data at hand, it<br/><br>
is concluded that the thermal boundary layer is on the<br/><br>
order of 1 mm thick. In this boundary layer the reactions<br/><br>
are delayed but not quenched.}},
author = {{Hultqvist, Anders and Engdar, Ulf and Johansson, Bengt and Klingmann, Jens}},
booktitle = {{SAE Transactions}},
language = {{eng}},
pages = {{1086--1098}},
publisher = {{SAE}},
title = {{Reacting Boundary Layers in Homogeneous Charge Compression Ignition (HCCI) Engine}},
url = {{http://www.sae.org/technical/papers/2001-01-1032}},
year = {{2001}},
}