Effect of liquid break-up model selection on simulated diesel spray and combustion characteristics

Journal article


Camm, J. 2021. Effect of liquid break-up model selection on simulated diesel spray and combustion characteristics. SAE Technical Papers.
AuthorsCamm, J.
Abstract

Accurate modelling for spray vapour fields is critical to enable adequate predictions of spray ignition and combustion characteristics of non-premixed reacting diesel sprays. Spray vapour characteristics are in turn controlled by liquid atomization and the KH-RT liquid jet break-up model is regularly used to predict this: with the KH model used for predicting primary break-up given its definition as a surface wave growth model, and the RT model used for predicting secondary break-up due to it being a drag based, stripping model. This paper investigates how the alteration of the switching position of the KH and RT sub-models within the KH-RT model impacts the resulting vapour field and ignition characteristics. The combustion prediction is handled by the implementation of a 54 species, 269 reaction skeletal mechanism utilising a Well Stirred Reactor model within the Star-CD CFD code. Following on from the derivation and implementation of an Ohnesorge based switch between the KH and RT sub-models, this model is now tested in igniting cases for an n-dodecane fuelled single holed injection representing the ECN “Spray A” condition, and is compared to the baseline Reitz-Diwakar model. Differences in flame behaviour, particularly within the temperature distribution, are seen and directly traced from the effect of liquid break-up position and model selection, through atomised droplet size distribution and mixture fraction distribution. Different criteria for judging the ignition delays and lift-off-lengths are compared, with all methods predicting very similar results for both models. The KH and RT sub-models are also tested against each other, with heavy instabilities seen when the RT model is solely applied to the spray. This correlates with the instabilities shown in the vapour fields, suggesting the enabling of the RT model near-nozzle is to be avoided.

KeywordsCombustion and combustion processes; Computational fluid dynamics
Year2021
JournalSAE Technical Papers
PublisherSAE International
ISSN0148-7191
2688-3627
Official URLhttps://saemobilus.sae.org/content/2021-01-0546/
Publication dates
Print06 Apr 2021
Publication process dates
Deposited22 Mar 2021
Accepted author manuscript
File Access Level
Restricted
Output statusIn press
Additional information

Technical Paper 2021-01-0546 presented at the SAE WCX Digital Summit.

Permalink -

https://repository.canterbury.ac.uk/item/8x4xx/effect-of-liquid-break-up-model-selection-on-simulated-diesel-spray-and-combustion-characteristics

  • 4
    total views
  • 0
    total downloads
  • 2
    views this month
  • 0
    downloads this month

Export as

Related outputs

The effect of droplet temperature model choice on gasoline droplet and spray simulation
Camm, J. 2021. The effect of droplet temperature model choice on gasoline droplet and spray simulation. SAE Technical Papers.
Investigation of fuel volatility on the heat transfer dynamics on piston surface due to the pulsed spray impingement
Zhou, Z-F, Liang, L., Hanis Mohd Murad, S., Camm, J. and Davy, M. 2021. Investigation of fuel volatility on the heat transfer dynamics on piston surface due to the pulsed spray impingement. International Journal of Heat and Mass Transfer. 170, p. 121008. https://doi.org/10.1016/j.ijheatmasstransfer.2021.121008
Predicting pMDI formulation thermophysical properties using activity coefficient models
Camm, J. and Versteeg, H.K. 2020. Predicting pMDI formulation thermophysical properties using activity coefficient models. Drug Delivery to the Lungs. 31.