Microdispensers

Retracting Fluid Dispenser

This example shows a simulation of a retracting fluid dispenser. The main concern here is the exact volume of fluid dispensed and how much is drawn back into the dispenser. The nozzle is only 1 millimeter in diameter, and at this scale surface tension is important because it dictates the amount of fluid deposited onto the substrate, similar to capillary flow. Using cylindrical coordinates with a specified contact angle between the resin-like fluid, the dispenser nozzle, and the substrate, the model is able to account for these effects. In addition, the Moving Objects Model was used to simulate the dispenser motion. Modeling the complexities of small, transient, free-surface flows along with moving objects can be easily accomplished using FLOW-3D.

Fluid dispenser: 3-D view of the computational domain

2-D animation of the retracting fluid dispenser in action, colored by pressure distribution