The piezoelectric valve-less pump - improved dynamic model

The piezoelectric valve-less pump is an attractive device to be used as a micro pump for low flow rates. The pump converts the reciprocating motion of a diaphragm, activated by a piezoelectric disk, into a pumping action. Instead of conventional valves, which have moving parts, nozzle/diffuser elements that have a preferential flow direction are used to direct the flow from the inlet to the outlet. In this paper, an improved dynamic model for the simulation of valve-less piezoelectric pumps is presented. The model is capable of accurate simulation of the pump performance including the natural frequency, flow rate, and pressure drop. The model is utilized here to study the effect of the driving frequency and the inlet/outlet length and diameter of the leading pipes on the pump performance. Comparison with experiments shows good agreement with a minimal number of adjusting parameters.