Single Oscillator, Dual-chamber Parallel Performance Analysis And Simulation Of The Valve Piezoelectric Micropump

During the last years, the rapid development of the Microelectric -Mechanics System(MEMS) is remarkable, but the Microfluidic System as a main research direction of the MEMS, has the wide market in all the fields. The micropump is the important executive unit of the Microfluidic System, and it is also the important symbol of the development level of the Microfluidic System. Now, many types of the micropump have been researched, and especially the valveless micropump has attracted much more attentions because of its simple structure.The thesis introduced the working principle of a valveless micropump with a single bimorph acutator and double chambers parallel connection and its structure, and analysed and researched its performances. First, based on the piezoelectricity and thin plate elastic theory and combined with the energy method, formulas for the calculation of the natural frequency and the static flexibility in invariable electric field were deduced for the boundary condition of the rigid supported plated. Then, based on the basis theory of fluid mechanics including the flow condition and the flow resistance, the thesis explained the uniflow mechanism, and illuminates the formulas of the commutation efficiency and the volume efficiency of the diffuser/nozzle pipe structure.However, the formulas and equations are not only complicated, but also difficult to resolve. Therefore, the Finite Element Analysis (FEA) method was used to simulate the micropump's performances in the thesis.The FEA software ANSYS was used to analyse the pizeoelectrics-structure couple of the acutator in order to obtain the acutator's geometry parameters which influence the acutor's performances, and the CFD software FLUENT was used to analyse the interior flow field of the diffuser/nozzle pipe.Synthetizing the analysis results of the micropump's structure, a group of optimized parameters were selected to design a valeless micropump's model and the ANSYS/FSI was ultilized to simulate the work process of the valeless micropump with a single bimorph acutator and double chambers parallel connection during a cycle. To exactly control the output flow of the valveless micropump, emphasized analyses how the voltage's amplitude and the frequency affect its output flow. The results of this thesis provide theoretical basis for structural design and parameters optimization of valveless micropump and have practicable reference value.