Wavelet Analysis of In-Cylinder LDV Measurements and Correlation Against Heat-Release
(1998) In SAE technical paper series 107.- Abstract
- Wavelet analysis was used to calculate turbulence and mean velocity levels for LDV measurements made in a four valve spark ignition engine. Five different camshafts were tested, and they produce significantly different flow behaviour. The standard cam gives tumble and with valve deactivation, swirl is produced. One camshaft with early
inlet valve closing and two camshafts with late inlet valve
closing were also tested. The wavelet toolbox for Matlab
version 5.1 has been used for the wavelet calculations.
The wavelet technique produces both time resolved and frequency resolved velocity information. The results indicate some influence of the turbulence frequency content
on the rate of... (More) - Wavelet analysis was used to calculate turbulence and mean velocity levels for LDV measurements made in a four valve spark ignition engine. Five different camshafts were tested, and they produce significantly different flow behaviour. The standard cam gives tumble and with valve deactivation, swirl is produced. One camshaft with early
inlet valve closing and two camshafts with late inlet valve
closing were also tested. The wavelet toolbox for Matlab
version 5.1 has been used for the wavelet calculations.
The wavelet technique produces both time resolved and frequency resolved velocity information. The results indicate some influence of the turbulence frequency content
on the rate of heat release. Correlation against eatrelease can be seen for different scales of turbulence.
The breakdown of the tumble (low frequency turbulence) into high frequency turbulence can be seen clearly. This
transition is not as clear with a swirling flow, where all frequencies are magnified equally at top dead center. The
choice of wavelet does not have a major impact on the
results. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/620685
- author
- Söderberg, Fredrik LU and Johansson, Bengt LU
- organization
- publishing date
- 1998
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- LDV, Wavelet, Engine, Combustion
- in
- SAE technical paper series
- volume
- 107
- article number
- 980483
- publisher
- Society of Automotive Engineers
- external identifiers
-
- scopus:85072449467
- ISSN
- 0148-7191
- DOI
- 10.4271/980483
- language
- English
- LU publication?
- yes
- id
- 5385bc3f-3169-448e-8be4-a03a2bb6ce90 (old id 620685)
- date added to LUP
- 2016-04-01 15:24:13
- date last changed
- 2022-01-28 05:10:41
@article{5385bc3f-3169-448e-8be4-a03a2bb6ce90,
abstract = {{Wavelet analysis was used to calculate turbulence and mean velocity levels for LDV measurements made in a four valve spark ignition engine. Five different camshafts were tested, and they produce significantly different flow behaviour. The standard cam gives tumble and with valve deactivation, swirl is produced. One camshaft with early<br/><br>
inlet valve closing and two camshafts with late inlet valve<br/><br>
closing were also tested. The wavelet toolbox for Matlab<br/><br>
version 5.1 has been used for the wavelet calculations.<br/><br>
<br/><br>
The wavelet technique produces both time resolved and frequency resolved velocity information. The results indicate some influence of the turbulence frequency content<br/><br>
on the rate of heat release. Correlation against eatrelease can be seen for different scales of turbulence.<br/><br>
The breakdown of the tumble (low frequency turbulence) into high frequency turbulence can be seen clearly. This<br/><br>
transition is not as clear with a swirling flow, where all frequencies are magnified equally at top dead center. The<br/><br>
choice of wavelet does not have a major impact on the<br/><br>
results.}},
author = {{Söderberg, Fredrik and Johansson, Bengt}},
issn = {{0148-7191}},
keywords = {{LDV; Wavelet; Engine; Combustion}},
language = {{eng}},
publisher = {{Society of Automotive Engineers}},
series = {{SAE technical paper series}},
title = {{Wavelet Analysis of In-Cylinder LDV Measurements and Correlation Against Heat-Release}},
url = {{http://dx.doi.org/10.4271/980483}},
doi = {{10.4271/980483}},
volume = {{107}},
year = {{1998}},
}