Date of Award

2025

Degree Name

Mechanical Engineering

College

College of Engineering and Computer Sciences

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Dr. Roozbeh “Ross” Salary

Second Advisor

Dr. Yousef Sardahi

Third Advisor

Dr. Arka Chattopadhyay

Abstract

Aerosol jet printing (AJP) is a 3D printing, advanced manufacturing process that generates an aerosol mist appropriate for fine printing small, low-volume electronic parts. The pneumatic aerosol jet printing technology’s virtual impactor is the focus of this study. In this technology, high velocity nitrogen gas aerosolizes various inks in the atomizer. The aerosolized stream of ink is then transported to a virtual impactor (VI) to become dense and concentrated as it begins to enter the deposition head for high precision electronics printing. AJP faces challenges in large-scale adoption due to challenges related to overspray, instability, ink clogging etc. There is discrepancy in the knowledge of the sources that cause such issues. Computationally simulating the pneumatic aerosol jet printing environment provides insights into unapparent ink flow behavior that may contribute to printing inefficiencies in the system. While the pneumatic atomizer and deposition head are sufficiently simulated and analyzed, the VI lacks the same focus. Therefore, simulating the VI environment provides a comprehensive understanding of the pneumatic AJP technology.

This is accomplished by 3D computational fluid dynamics (CFD) modeling and simulation of the VI system in ANSYS Fluent. First, an initial characterization of the system is completed by creating a 3D CAD model based on x-ray images of the VI by Optomec and a subsequent CFD analysis using a turbulent k-epsilon model. Second, design investigations and corresponding CFD simulations are conducted by altering critical design parameters in the system such as the impactor and collector lengths, impactor to collector diameter ratio, and aerodynamic transport channels (ATC) count and diameter. The initial characterization study revealed that the VI experiences nonuniform flow removal, flow circulation, and increased EGF port velocity.

Subject(s)

Mechanical engineering.

Additive manufacturing.

Computational fluid dynamics.

Three-dimensional printing.

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