This work investigates surface impingement of monodispersed diesel drop trains using computational simulations. The three-dimensional simulations include high-speed impact of micrometer-sized fuel drops onto initially dry and wetted stainless steel substrates. The drop size and impact velocity are representative of fuel injection conditions in internal combustion engines (ICEs). The drop trains serve as a simplified representation of fuel spray. To accurately capture the film that naturally develops on initially dry substrates, a dynamic diesel-stainless steel contact angle model was developed using experiments of single drop impact under ICE representative temperature. Simulations are presented for a highly splashing case and the effects of a pre-existing film on splashing dynamics were investigated, including the temporal evolution of splashed mass and film thickness. It was concluded that for thin films, the effect of pre-existing film thickness is less significant than in single drop impingement. Secondary droplet characterization was performed on simulation results, leading to instantaneous and time-averaged distributions of secondary droplet size, velocity magnitude, and trajectory angle. It was found that for each drop impingement, approximately 58% of the splashed mass is from the impinging drop itself, while the remainder of the splashed mass is composed of film liquid. From a high resolution case, details of secondary droplet formation are observed and three distinct phases of secondary droplet formation are identified. The detailed analysis of drop train impingement under engine-relevant conditions serves as a first step toward a robust understanding of fuel impingement and the development of cleaner and more efficient ICEs.
Markt, D., et al. "High-speed impact of micron-sized diesel drop trains—Splashing dynamics, secondary droplet formation, and effects of pre-existing film thickness." Physics of Fluids, vol. 33, no. 10, Oct. 2021. https://doi.org/10.1063/5.0068908
Markt, D., Raessi, M., Lee, S. -Y., & Zhu, X. (2021). High-speed impact of micron-sized diesel drop trains—Splashing dynamics, secondary droplet formation, and effects of pre-existing film thickness. Physics of Fluids, 33(10). https://doi.org/10.1063/5.0068908
Markt, D., Raessi, M., Lee, S. -Y., et al., "High-speed impact of micron-sized diesel drop trains—Splashing dynamics, secondary droplet formation, and effects of pre-existing film thickness," Physics of Fluids 33, no. 10 (2021), https://doi.org/10.1063/5.0068908
@article{osti_1978970,
author = {Markt, D. and Raessi, M. and Lee, S. -Y. and Zhu, X.},
title = {High-speed impact of micron-sized diesel drop trains—Splashing dynamics, secondary droplet formation, and effects of pre-existing film thickness},
annote = {This work investigates surface impingement of monodispersed diesel drop trains using computational simulations. The three-dimensional simulations include high-speed impact of micrometer-sized fuel drops onto initially dry and wetted stainless steel substrates. The drop size and impact velocity are representative of fuel injection conditions in internal combustion engines (ICEs). The drop trains serve as a simplified representation of fuel spray. To accurately capture the film that naturally develops on initially dry substrates, a dynamic diesel-stainless steel contact angle model was developed using experiments of single drop impact under ICE representative temperature. Simulations are presented for a highly splashing case and the effects of a pre-existing film on splashing dynamics were investigated, including the temporal evolution of splashed mass and film thickness. It was concluded that for thin films, the effect of pre-existing film thickness is less significant than in single drop impingement. Secondary droplet characterization was performed on simulation results, leading to instantaneous and time-averaged distributions of secondary droplet size, velocity magnitude, and trajectory angle. It was found that for each drop impingement, approximately 58% of the splashed mass is from the impinging drop itself, while the remainder of the splashed mass is composed of film liquid. From a high resolution case, details of secondary droplet formation are observed and three distinct phases of secondary droplet formation are identified. The detailed analysis of drop train impingement under engine-relevant conditions serves as a first step toward a robust understanding of fuel impingement and the development of cleaner and more efficient ICEs.},
doi = {10.1063/5.0068908},
url = {https://www.osti.gov/biblio/1978970},
journal = {Physics of Fluids},
issn = {ISSN 1070-6631},
number = {10},
volume = {33},
place = {United States},
publisher = {American Institute of Physics (AIP)},
year = {2021},
month = {10}}
Michigan Technological University, Houghton, MI (United States); University of Massachusetts, Dartmouth, MA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE); Department of Defense (DoD); Office of Naval Research (ONR); National Science Foundation (NSF)
Grant/Contract Number:
EE0007292
OSTI ID:
1978970
Alternate ID(s):
OSTI ID: 1827761
Journal Information:
Physics of Fluids, Journal Name: Physics of Fluids Journal Issue: 10 Vol. 33; ISSN 1070-6631