Three-dimensional numerical simulation of air-flow in inkjet print-zones.

• The air-flow due to droplet entrainment in inkjet print-zones is simulated for a range of conditions. • Increasing the pen-to-paper spacing causes the vortex upstream of the print-zone to become deformed. • Adding through flow from the inlet to outlet is an effective remedy for the print defect. Air-flow oscillations in inkjet print-zones give rise to undesirable print defects due to misplacement of low Stokes number satellite droplets. The problem is studied numerically using a novel dispersed-phase continuum method, that, due to the separation of length scales, permits the force exerted by the multitude of high Stokes number main droplets to be modelled as a continuous smooth field. The oscillations seem to be linked to the deformation of the primary vortex upstream of the print-zone. It is also shown that introducing extra flow in the direction of the paper motion is an effective remedy for the oscillations. [ABSTRACT FROM AUTHOR]