Designing Bubble Jets
There are a wide range of bubble models in FLOW-3D from
simple constant pressure models to complex vapor bubbles that include heat transfer,
phase change, and pressure dynamics within both the fluid and vapor.
Alternative Drop Ejector Architecture from Eastman Kodak
The image below shows how a vapor bubble forms explosively once the superheat temperature is reached in the fluid. The bubble is assumed to have homogeneous pressure and temperature, the dynamics of which are governed by the Clapeyron equation for the vapor. Mass and heat exchange at the vapor/liquid interface continues as the bubble expands, with the mass flux determined from kinetic theory. Surface tension and viscous forces are also included in the simulations.
Comparison between physical experiments (top row) and
simulation (bottom row) – Early experimental device configuration.
Image courtesy of Eastman Kodak