Generation and Propagation Characteristics of an Auto-Ignition Flame Kernel Caused by the Oblique Shock in a Supersonic Flow Regime
(2022) In Energies 15(9).- Abstract
The auto-ignition caused by oblique shocks was investigated experimentally in a supersonic flow regime, with the incoming flow at a Mach number of 2.5. The transient characteristics of the auto-ignition caused by shock evolvements were recorded with a schlieren photography system, and the initial flame kernel generation and subsequent propagation were recorded using a high-speed camera. The fuel mixing characteristics were captured using NPLS (nanoparticle-based planar laser scattering method). This work aimed to reveal the flame spread mechanism in a supersonic flow regime. The effects of airflow total temperature, fuel injection pressure, and cavity length in the process of auto-ignition and on the auto-ignitable boundary were... (More)
The auto-ignition caused by oblique shocks was investigated experimentally in a supersonic flow regime, with the incoming flow at a Mach number of 2.5. The transient characteristics of the auto-ignition caused by shock evolvements were recorded with a schlieren photography system, and the initial flame kernel generation and subsequent propagation were recorded using a high-speed camera. The fuel mixing characteristics were captured using NPLS (nanoparticle-based planar laser scattering method). This work aimed to reveal the flame spread mechanism in a supersonic flow regime. The effects of airflow total temperature, fuel injection pressure, and cavity length in the process of auto-ignition and on the auto-ignitable boundary were investigated and analyzed. From this work, it was found that the initial occurrence of auto-ignition is first induced by oblique shocks and then propagated upstream to the recirculation region, to establish a sustained flame. The auto-ignition performance can be improved by increasing the injection pressure and airflow total temperature. In addition, a cavity with a long length has benefits in controlling the flame spread from the induced state to a sustained state. The low-speed recirculating region created in the cavity is beneficial for the flame spread, which has the function of flame-holding and prevents the flame from being blown away.
(Less)
- author
- Xi, Wenxiong ; Xu, Mengyao ; Liu, Chaoyang LU ; Liu, Jian LU and Sunden, Bengt LU
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- auto-ignition, initial flame kernel, oblique shock, recirculating region, supersonic flow
- in
- Energies
- volume
- 15
- issue
- 9
- article number
- 3356
- publisher
- MDPI AG
- external identifiers
-
- scopus:85130633231
- ISSN
- 1996-1073
- DOI
- 10.3390/en15093356
- language
- English
- LU publication?
- yes
- id
- 49df0566-4321-47ea-a6b6-351b859d9550
- date added to LUP
- 2022-08-24 15:07:54
- date last changed
- 2025-04-04 14:47:28
@article{49df0566-4321-47ea-a6b6-351b859d9550,
abstract = {{<p>The auto-ignition caused by oblique shocks was investigated experimentally in a supersonic flow regime, with the incoming flow at a Mach number of 2.5. The transient characteristics of the auto-ignition caused by shock evolvements were recorded with a schlieren photography system, and the initial flame kernel generation and subsequent propagation were recorded using a high-speed camera. The fuel mixing characteristics were captured using NPLS (nanoparticle-based planar laser scattering method). This work aimed to reveal the flame spread mechanism in a supersonic flow regime. The effects of airflow total temperature, fuel injection pressure, and cavity length in the process of auto-ignition and on the auto-ignitable boundary were investigated and analyzed. From this work, it was found that the initial occurrence of auto-ignition is first induced by oblique shocks and then propagated upstream to the recirculation region, to establish a sustained flame. The auto-ignition performance can be improved by increasing the injection pressure and airflow total temperature. In addition, a cavity with a long length has benefits in controlling the flame spread from the induced state to a sustained state. The low-speed recirculating region created in the cavity is beneficial for the flame spread, which has the function of flame-holding and prevents the flame from being blown away.</p>}},
author = {{Xi, Wenxiong and Xu, Mengyao and Liu, Chaoyang and Liu, Jian and Sunden, Bengt}},
issn = {{1996-1073}},
keywords = {{auto-ignition; initial flame kernel; oblique shock; recirculating region; supersonic flow}},
language = {{eng}},
number = {{9}},
publisher = {{MDPI AG}},
series = {{Energies}},
title = {{Generation and Propagation Characteristics of an Auto-Ignition Flame Kernel Caused by the Oblique Shock in a Supersonic Flow Regime}},
url = {{http://dx.doi.org/10.3390/en15093356}},
doi = {{10.3390/en15093356}},
volume = {{15}},
year = {{2022}},
}