A level-set method for simulation of a thermal inkjet process

A numerical approach is presented for computing a thermal inkjet process, in which bubble growth and collapse acts as a driving mechanism for ink droplet ejection. The liquid-vapor and liquid-air interfaces are tracked by a level-set method which is modified to include the effect of phase change at the liquid-vapor interface and is extended to treat the contact angle condition at an immersed solid surface. The compressibility effect of a bubble is also included in the analysis to account for the high vapor pressure caused by instantaneous bubble nucleation. The whole process of the thermal inkjet, including jet breaking, satellite droplet formation, and ink refill, as well as bubble growth and collapse, is simulated without employing a simplified bubble growth model.