Flow of Quasi-2D Emulsion Droplets Through Small Openings

We examine how various parameters affect the flow rate of quasi-2D soft particles moving through tight openings. To observe this, we create thin hopper-shaped chambers which have a small exit for the particles to flow through. We fill the chambers with monodisperse oil-in-water emulsions with a soap surfactant. We use microscopy to observe the droplets moving through the chamber. We find faster flow rates when there are more droplets in the chamber (providing a larger pressure head) and with larger exit sizes. We fit the flow rate to a modified Beverloo equation with an extra term for the height of the particles pushing the droplets through the opening.