Toward Predictive Simulations of Aerosol Jet Printing by Computational Fluid Dynamics—A Progress Report

Abstract Aerosol jet printing (AJP) is an ink-depositing additive manufacturing method used in the production of small-scale electronic devices, utilizing a gas flow to aerodynamically print conductive lines. Although the process shows promise, its potential is limited by quality-limiting phenomena. Predicting their occurrence can be a time-consuming and complex process due to the strong sensitivity of the process to individual operating conditions, limiting reproducibility. This oftentimes can render experimental setups uneconomical. Numerical methods, such as computational fluid dynamics, are appealing due to their ability to easily change process parameters, enabling cost-effective analysis of several process setups. As we consider turbulence to be one of the primary causes of quality limitations, it is crucial to predict turbulent properties accurately when numerically modeling the flow. Traditional turbulence modeling within a Reynolds-averaged Navier–Stokes (RANS) approach has been found to be inadequate for accurately predicting turbulent quantities of low Reynolds number free jets, rendering it unsuitable as a tool for investigations of aerosol jet printing. In the study presented, a first step toward three-dimensional investigation of a free jet under aerosol jet printing operating conditions using large eddy simulation (LES) is proposed. The accuracy of the model regarding predictability of turbulent quantities is assessed in a first manner by comparing turbulent transition points to experimental findings and found to be in overall satisfactory agreement.