view all projects
 

an experiment on valveless pumping
(click on an image for a larger view)
Numerical simulations by E. Jung and C. Peskin have demonstrated that a closed circuit of fluid can produce a directional flow under periodic forcing. The intriguing aspect of the phenomenon is the absence of valves in the system. The simulations show that the flow speed and direction depends upon the frequency and amplitude of excitation. Inspired by their studies, we performed a tabletop experiment studying the 3D valveless pump. We have observed the flow reversal at certain pumping frequencies and amplitudes. By this summer, we will be able to address the phenomenon more quantitatively, using flow visualization and LDV measurements to study the phenomenon.
A simple model of a valveless pump: It consists of three parts, a hard (transparent) tube and two soft, elastic (and translucent) tube segments. When a periodic force is applied to one of the soft segments, a directional flow is induced in the circuit.
A closeup of the pumping mechanism: At the upper-left corner, a mechanical "finger" is driven periodically against the soft tubing . Its amplitude and frequency can be adjusted continuously.
view all projects