An efficient simulation that can precisely predict the process of spray formation would be of great benefit to a variety of important applications such as combustion engines, spray cooling, and thin-film fabrication. Two fundamental barriers in advancing simulation of spray formation are 1) the lack of a comprehensive understanding of the effects of inlet conditions on the destabilization and breakup of liquids; and 2) the extreme computational cost of a high-fidelity simulation that can capture all the physical scales. This project aims to tackle these two challenges by characterizing the impact of inlet conditions on spray formation through high-fidelity simulation. The proposed work will be focused on sprays formed by planar air-blast atomizers to better understand the fundamental fluid dynamics. The physical insights of spray formation processes obtained in the project will assist engineers in developing new techniques to control spray features. The educational plan will be developed in collaboration with Baylor's Mayborn Museum's NSF-funded Portal to the Public program and the Learning Experience (LEx) Labs of the Region 12 Educational Service Center.

The specific objectives of the proposed project are: 1) to characterize through high-fidelity simulation the effects of inlet gas turbulence, asymmetry in the gas inflow velocity, and geometry of gas inlets on interfacial instability and spray formation; 2) to establish a novel sub-grid model based on topological skeletonization of liquid structures; and 3) to create educational activities based on our simulation and modeling research to inspire K-12 students, including those in grades 7-12 and those with physical limitations, to consider a STEM education and career pathway. Former studies were generally limited to basic features of inlet conditions, such as the mean velocity profile, and finer aspects such as inlet turbulence and inlet flow asymmetry are usually assumed to be secondary. This assumption has been challenged by recent experiments and will be systematically examined in this project. The research will provide a comprehensive understanding of the impact of inlet conditions on interfacial instability and spray formation. The skeletonization method, which is widely used in computer graphics, will be employed to develop a novel sub-grid model for spray formation. The surface, curve, and point skeletons, representing micro-scale liquid sheets, filaments, and droplets formed in atomization, will provide a framework to model the unresolved dynamics, deformation, and breakup of these liquid structures. The use of the new model will significantly reduce the computational cost of numerical simulation of spray formation.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Project Start
Project End
Budget Start
2020-06-01
Budget End
2025-05-31
Support Year
Fiscal Year
2019
Total Cost
$434,512
Indirect Cost
Name
Baylor University
Department
Type
DUNS #
City
Waco
State
TX
Country
United States
Zip Code
76798