Optimization and Numerical Flow Analysis of a Valveless Micropump

Abstract

This paper presents thermal and flow analyses and optimization of a bi-directional valve-less micropump. The bi-directional pump does not use mechanical check valves but takes advantage of the viscosity variation according to temperature. When there is a viscosity difference between two outlet chokes, the flow rate of one choke becomes greater than that of the other, which results in flow rectification in one direction. The benefits of this type of micropump are: its structure is simple, and it allows bi-directional pumping. In order to investigate the behavior of the micropump, an FEA model is made for the whole physical domains, and coupled thermal and fluid flow analyses are conducted using a commercial code throughout the entire working cycle. The rectification efficiency and fluid flow rate are designated as the objective function for optimization. To improve the performance of the pump, important thermal parameters-heat flux, preheating time and heating time-are selected and optimized.