Study on ignition process and flame expansion and propagation characteristics in jet-cooled pilot flameholders using image processing techniques
(2022) In Aerospace Science and Technology 129.- Abstract
Wall-type pilot flameholder has been used in aero-engines to effectively create a stable ignition source and achieve an excellent ignition performance in high-velocity flows. The ignition delay, flame propagation, and flame boundary are crucial characteristics to evaluate the performance of pilot flameholders. Previous work displayed the significantly changed ignition performance and flow features of the wall flameholder when jet cooling schemes were adopted, indicating that the ignition process and the flame features strongly depend on the cooling jet and the optimal design of jet cooling schemes needs further investigation. Therefore, in this study, two practical image processing algorithms are developed to characterize the flame... (More)
Wall-type pilot flameholder has been used in aero-engines to effectively create a stable ignition source and achieve an excellent ignition performance in high-velocity flows. The ignition delay, flame propagation, and flame boundary are crucial characteristics to evaluate the performance of pilot flameholders. Previous work displayed the significantly changed ignition performance and flow features of the wall flameholder when jet cooling schemes were adopted, indicating that the ignition process and the flame features strongly depend on the cooling jet and the optimal design of jet cooling schemes needs further investigation. Therefore, in this study, two practical image processing algorithms are developed to characterize the flame development of the ignition process, reveal the effect of cooling schemes on the ignition delay time, and quantitatively analyze the flame area and expansion ratio of the wall flameholder during stable combustion. Two image processing methods proposed based on MATLAB algorithms exhibit effectiveness in studying the ignition process and flame expansion characteristics. The ignition process is divided into four phases: kernel generation, kernel propagation, flame growth, and stable combustion. Meanwhile, the ignition delay time is identified by counting the total pixels of the flame projected region during the ignition process. The edge detection and pixel statistics of the flame projected region in the binary luminosity image show the flame boundary and expansion ratio under various working conditions. It was found that the cooling jet angle has a significant impact on the ignition process, ignition delay time, flame propagation, and steady flame features. The pressure-driven gas jet cooling scheme with a smaller jet angle and the external-inhaled air cooling scheme with a larger jet angle present a better capability of ignition and flame expansion and propagation.
(Less)
- author
- Chen, Yuqian LU ; Fan, Yuxin ; Han, Qixiang and Bai, Xue Song LU
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Edge detection, Flame expansion, Ignition delay, Ignition process, Image processing, Pilot flameholder
- in
- Aerospace Science and Technology
- volume
- 129
- article number
- 107807
- publisher
- Elsevier Masson SAS
- external identifiers
-
- scopus:85136160684
- ISSN
- 1270-9638
- DOI
- 10.1016/j.ast.2022.107807
- language
- English
- LU publication?
- yes
- id
- e574e954-b60b-4caf-b621-678b74929fd6
- date added to LUP
- 2022-09-19 14:34:58
- date last changed
- 2023-11-06 18:46:12
@article{e574e954-b60b-4caf-b621-678b74929fd6,
abstract = {{<p>Wall-type pilot flameholder has been used in aero-engines to effectively create a stable ignition source and achieve an excellent ignition performance in high-velocity flows. The ignition delay, flame propagation, and flame boundary are crucial characteristics to evaluate the performance of pilot flameholders. Previous work displayed the significantly changed ignition performance and flow features of the wall flameholder when jet cooling schemes were adopted, indicating that the ignition process and the flame features strongly depend on the cooling jet and the optimal design of jet cooling schemes needs further investigation. Therefore, in this study, two practical image processing algorithms are developed to characterize the flame development of the ignition process, reveal the effect of cooling schemes on the ignition delay time, and quantitatively analyze the flame area and expansion ratio of the wall flameholder during stable combustion. Two image processing methods proposed based on MATLAB algorithms exhibit effectiveness in studying the ignition process and flame expansion characteristics. The ignition process is divided into four phases: kernel generation, kernel propagation, flame growth, and stable combustion. Meanwhile, the ignition delay time is identified by counting the total pixels of the flame projected region during the ignition process. The edge detection and pixel statistics of the flame projected region in the binary luminosity image show the flame boundary and expansion ratio under various working conditions. It was found that the cooling jet angle has a significant impact on the ignition process, ignition delay time, flame propagation, and steady flame features. The pressure-driven gas jet cooling scheme with a smaller jet angle and the external-inhaled air cooling scheme with a larger jet angle present a better capability of ignition and flame expansion and propagation.</p>}},
author = {{Chen, Yuqian and Fan, Yuxin and Han, Qixiang and Bai, Xue Song}},
issn = {{1270-9638}},
keywords = {{Edge detection; Flame expansion; Ignition delay; Ignition process; Image processing; Pilot flameholder}},
language = {{eng}},
publisher = {{Elsevier Masson SAS}},
series = {{Aerospace Science and Technology}},
title = {{Study on ignition process and flame expansion and propagation characteristics in jet-cooled pilot flameholders using image processing techniques}},
url = {{http://dx.doi.org/10.1016/j.ast.2022.107807}},
doi = {{10.1016/j.ast.2022.107807}},
volume = {{129}},
year = {{2022}},
}