Mechanical Engineering MS Thesis Defense by Mr. David Markt Jr.
When: Friday,
January 22, 2021
11:00 AM
-
1:00 PM
Where: > See description for location
Description: Mechanical Engineering MS Thesis Defense by
Mr. David Markt Jr.
DATE:
January 22, 2021
TIME:
11:00 a.m. to 1:00 p.m.
LOCATION:
Virtual; Zoom link: https://umassd.zoom.us/j/98690657717?pwd=dVNMOGZQVlFXWlZKNjh5eG91Rnd6QT09
Meeting ID:
986 9065 7717
Passcode:
797661
TOPIC:
IMPINGEMENT OF HYDROCARBON FUEL DROP TRAINS: DEVELOPMENT OF AN ENHANCED SPRAY-WALL INTERACTION SUBMODEL
ABSTRACT:
This work investigates surface impingement of mono-dispersed trains of hydrocarbon fuels using computational simulations. The three-dimensional simulations include ethanol and diesel drop impingement onto initially dry and wetted stainless steel substrates. The high-speed micron-sized diesel 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. The impingement frequency at which drop trains transition from depositing to splashing was identified. Furthermore, effects of impingement frequency on splashed mass were quantified. Additionally, the effects of a pre-existing film on splashing dynamics were investigated at various film thicknesses, where the temporal evolution of splashed mass was obtained. Secondary droplet characterization was performed on simulation results using a robust algorithm that scrutinizes the volume fraction and velocity fields. This analysis provides insights into the stages of secondary droplet formation. Instantaneous and time-averaged distributions of secondary droplet size, velocity magnitude and trajectory angle are reported. The splashed mass ratio and secondary droplet characterization results were compared to commonly used spray-wall interaction (SWI) sub-models, which are heavily relied upon in a Lagrangian-Eulerian (LE) fuel injection modeling framework. The comparison reveals the SWI sub-models suffer from significant inaccuracy under engine-relevant conditions. Finally, a new SWI sub-model is proposed for diesel fuel injection based on the simulation results. The model provides correlations for splashed mass ratio and secondary droplet size and velocity as a function of a nondimensional velocity. To the best of the author's knowledge, the proposed model is the first SWI sub-model based on engine-relevant drop impingements, which is expected to improve the accuracy of LE combustion simulations.
ADVISOR:
Dr. Mehdi Raessi, Associate Professor of Mechanical Engineering, College of Engineering, UMassD
COMMITTEE MEMBERS:
-Dr. Alex Fowler, Professor of Mechanical Engineering, UMassD
-Dr. Banafsheh Seyedaghazadeh, Assistant Professor of Mechanical Engineering, College of Engineering, UMassD
Open to the public. All MNE students are encouraged to attend.
For more information, please contact Dr. Mehdi Raessi (mraessi@umassd.edu, 508-999-8496).
Thank you,
Sue Cunha, Administrative Assistant
UMass Dartmouth
Mechanical Engineering Department
scunha@umassd.edu
508-999-8492
Mr. David Markt Jr.
DATE:
January 22, 2021
TIME:
11:00 a.m. to 1:00 p.m.
LOCATION:
Virtual; Zoom link: https://umassd.zoom.us/j/98690657717?pwd=dVNMOGZQVlFXWlZKNjh5eG91Rnd6QT09
Meeting ID:
986 9065 7717
Passcode:
797661
TOPIC:
IMPINGEMENT OF HYDROCARBON FUEL DROP TRAINS: DEVELOPMENT OF AN ENHANCED SPRAY-WALL INTERACTION SUBMODEL
ABSTRACT:
This work investigates surface impingement of mono-dispersed trains of hydrocarbon fuels using computational simulations. The three-dimensional simulations include ethanol and diesel drop impingement onto initially dry and wetted stainless steel substrates. The high-speed micron-sized diesel 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. The impingement frequency at which drop trains transition from depositing to splashing was identified. Furthermore, effects of impingement frequency on splashed mass were quantified. Additionally, the effects of a pre-existing film on splashing dynamics were investigated at various film thicknesses, where the temporal evolution of splashed mass was obtained. Secondary droplet characterization was performed on simulation results using a robust algorithm that scrutinizes the volume fraction and velocity fields. This analysis provides insights into the stages of secondary droplet formation. Instantaneous and time-averaged distributions of secondary droplet size, velocity magnitude and trajectory angle are reported. The splashed mass ratio and secondary droplet characterization results were compared to commonly used spray-wall interaction (SWI) sub-models, which are heavily relied upon in a Lagrangian-Eulerian (LE) fuel injection modeling framework. The comparison reveals the SWI sub-models suffer from significant inaccuracy under engine-relevant conditions. Finally, a new SWI sub-model is proposed for diesel fuel injection based on the simulation results. The model provides correlations for splashed mass ratio and secondary droplet size and velocity as a function of a nondimensional velocity. To the best of the author's knowledge, the proposed model is the first SWI sub-model based on engine-relevant drop impingements, which is expected to improve the accuracy of LE combustion simulations.
ADVISOR:
Dr. Mehdi Raessi, Associate Professor of Mechanical Engineering, College of Engineering, UMassD
COMMITTEE MEMBERS:
-Dr. Alex Fowler, Professor of Mechanical Engineering, UMassD
-Dr. Banafsheh Seyedaghazadeh, Assistant Professor of Mechanical Engineering, College of Engineering, UMassD
Open to the public. All MNE students are encouraged to attend.
For more information, please contact Dr. Mehdi Raessi (mraessi@umassd.edu, 508-999-8496).
Thank you,
Sue Cunha, Administrative Assistant
UMass Dartmouth
Mechanical Engineering Department
scunha@umassd.edu
508-999-8492
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