Narayan V. Deshpande

Fluid Mechanics of Bubble Growth and Collapse in a Thermal Ink Jet Printhead

A three-dimensional fluid mechanics analysis of a bubble growth and collapse has been carried out for some thermal ink jet printhead geometries. For that purpose, a computer code has been developed which can handle multi-valued free surfaces that arise in such geometries. This paper presents sample results which show how the bubble grows and collapses, and how it differs with geometrical changes.

Significance of inertia and resistance in fluidics of thermal ink-jet transducers

The fluid flow in the thermal ink jet transducers is highly dynamic in the sense that at no time during its operation the flow reaches a steady state condition. The transient flow is affected by the inertial and viscous effects. These two effects are reflected through the inertance and resistance parameters of the transducer geometry. In this paper we will present a general background on the inertance and resistance parameters, present a method for calculating these parameters for a given 3D geometry, and briefly outline their role in the ink drop ejection process.