Numerical study on drop-on-demand droplet formation dynamics

Inkjet printing technology has been applied in many industrial fields for its significant usefulness. The drop-on-demand droplet formation dynamics was studied numerically based on the VOF and CSF method. Droplet formation was modeled by imposing a vertical velocity pulse waveform perturbation. The effects of printhead geometry and fluid properties on droplet ejection stability were analyzed. Simulation results make clear that choosing an appropriate printing fluid with relatively lower density and viscosity or higher surface tension can improve the droplet ejection stability. Designing the printhead with a larger inclination of outlet is also a key way to improve the droplet ejection stability. In addition, droplet ejection stability becomes better as Z increased or Ca decreased.