Effects of ambient pressure and nozzle diameter on ignition characteristics in diesel spray combustion
Ong, Jiun Cai ; Walther, Jens Honore ; Xu, Shijie LU
; Zhong, Shenghui
LU
; Bai, Xue Song
LU
and Pang, Kar Mun
(2021)
In Fuel
290.
- Abstract
Numerical simulations are performed to investigate the effects of ambient density (ρam) and nozzle diameter (Dnoz) on the ignition characteristic of diesel spray combustion under engine-like conditions. A total of nine cases which consist of different ρam of 14.8, 30.0, and 58.5 kg/m3 and different Dnoz of 100, 180, and 363 μm are considered. The results show that the predicted ignition delay times are in good agreement with measurements. The current results show that the mixture at the spray central region becomes more fuel-rich as Dnoz increases. This leads to a shift in the high-temperature ignition location from the spray tip towards the spray periphery as... (More)
Numerical simulations are performed to investigate the effects of ambient density (ρam) and nozzle diameter (Dnoz) on the ignition characteristic of diesel spray combustion under engine-like conditions. A total of nine cases which consist of different ρam of 14.8, 30.0, and 58.5 kg/m3 and different Dnoz of 100, 180, and 363 μm are considered. The results show that the predicted ignition delay times are in good agreement with measurements. The current results show that the mixture at the spray central region becomes more fuel-rich as Dnoz increases. This leads to a shift in the high-temperature ignition location from the spray tip towards the spray periphery as Dnoz increases at ρam of 14.8 kg/m3. At higher ρam of 30.0 and 58.5 kg/m3, the ignition locations for all Dnoz cases occur at the spray periphery due to shorter ignition timing and the overly fuel-rich spray central region. The numerical results show that the first ignition location during the high-temperature ignition occurs at the fuel-rich region at ρam⩽30.0 kg/m3 across different Dnoz. At ρam=58.5 kg/m3, the ignition occurs at the fuel-lean region for the 100 and 180 μm cases, but at the fuel-rich region for the 363 μm nozzle case. This distinctive difference in the result at 58.5 kg/m3 is likely due to the relatively longer ignition delay time in the 363 μm nozzle case. Furthermore, the longer ignition delay time as Dnoz increases can be related to the higher local scalar dissipation rate in the large nozzle case.
(Less)
- author
- Ong, Jiun Cai
; Walther, Jens Honore
; Xu, Shijie
LU
; Zhong, Shenghui
LU
; Bai, Xue Song
LU
and Pang, Kar Mun
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Ambient density effect, Ignition process, Nozzle diameter effect, Spray flame, Transported probability density function
- in
- Fuel
- volume
- 290
- article number
- 119887
- publisher
- Elsevier
- external identifiers
-
- scopus:85098726639
- ISSN
- 0016-2361
- DOI
- 10.1016/j.fuel.2020.119887
- language
- English
- LU publication?
- yes
- id
- cebe610f-f6df-4093-8e42-18e173609bb8
- date added to LUP
- 2021-01-12 13:56:23
- date last changed
- 2022-04-26 23:24:27
@article{cebe610f-f6df-4093-8e42-18e173609bb8,
abstract = {{<p>Numerical simulations are performed to investigate the effects of ambient density (ρ<sub>am</sub>) and nozzle diameter (D<sub>noz</sub>) on the ignition characteristic of diesel spray combustion under engine-like conditions. A total of nine cases which consist of different ρ<sub>am</sub> of 14.8, 30.0, and 58.5 kg/m<sup>3</sup> and different D<sub>noz</sub> of 100, 180, and 363 μm are considered. The results show that the predicted ignition delay times are in good agreement with measurements. The current results show that the mixture at the spray central region becomes more fuel-rich as D<sub>noz</sub> increases. This leads to a shift in the high-temperature ignition location from the spray tip towards the spray periphery as D<sub>noz</sub> increases at ρ<sub>am</sub> of 14.8 kg/m<sup>3</sup>. At higher ρ<sub>am</sub> of 30.0 and 58.5 kg/m<sup>3</sup>, the ignition locations for all D<sub>noz</sub> cases occur at the spray periphery due to shorter ignition timing and the overly fuel-rich spray central region. The numerical results show that the first ignition location during the high-temperature ignition occurs at the fuel-rich region at ρ<sub>am</sub>⩽30.0 kg/m<sup>3</sup> across different D<sub>noz</sub>. At ρ<sub>am</sub>=58.5 kg/m<sup>3</sup>, the ignition occurs at the fuel-lean region for the 100 and 180 μm cases, but at the fuel-rich region for the 363 μm nozzle case. This distinctive difference in the result at 58.5 kg/m<sup>3</sup> is likely due to the relatively longer ignition delay time in the 363 μm nozzle case. Furthermore, the longer ignition delay time as D<sub>noz</sub> increases can be related to the higher local scalar dissipation rate in the large nozzle case.</p>}},
author = {{Ong, Jiun Cai and Walther, Jens Honore and Xu, Shijie and Zhong, Shenghui and Bai, Xue Song and Pang, Kar Mun}},
issn = {{0016-2361}},
keywords = {{Ambient density effect; Ignition process; Nozzle diameter effect; Spray flame; Transported probability density function}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Fuel}},
title = {{Effects of ambient pressure and nozzle diameter on ignition characteristics in diesel spray combustion}},
url = {{http://dx.doi.org/10.1016/j.fuel.2020.119887}},
doi = {{10.1016/j.fuel.2020.119887}},
volume = {{290}},
year = {{2021}},
}