# Simulation Study of Ink Droplet Spraying Based on Sand 3D Printing

## TL;DR

This study uses simulations to improve ink droplet control in 3D sand printing, enhancing precision and stability in the manufacturing process.

## Contribution

The study introduces a CFD-based simulation approach to optimize ink properties for precise droplet formation in sand mold 3D printing.

## Key findings

- The VOF model effectively simulates droplet generation, breakup, and flight in piezoelectric jetting.
- Viscosity, surface tension, and inlet velocity significantly influence droplet ejection stability and precision.
- Recommended ink property ranges are provided to enhance industrial sand mold 3D printing performance.

## Abstract

To address the challenge of imprecise micro-droplet formation control in piezoelectric jetting devices used in sand mold 3D printing and apply on-demand inkjet printing technology to sand mold manufacturing, this study first explains the working principle of a piezoelectric shear-mode printhead. A mathematical model of the droplet ejection process is then established based on Computational Fluid Dynamics (CFD). Building upon this model, numerical simulations of droplet generation, breakup, and flight are conducted by using the Volume of Fluid (VOF) model within the Fluent module of the Workbench 2020 R2 platform. Finally, under consistent driving conditions, the effects of key parameters—viscosity, surface tension, and inlet velocity—on the ejection process are investigated through simulation. Based on the results, appropriate ranges and recommended values for ink properties are determined. This study provides significant engineering value for improving the stability and precision of droplet formation in industrial sand mold 3D printing.