Numerical Simulation on the design of Inlet and Outlet in the Valveless Micropump
Date Issued
2011
Date
2011
Author(s)
Lin, Chia-Hsiang
Abstract
This paper use the ANSYS software to do numerical analysis of flow rate for the valveless nozzle/diffuser-based micropump. By varying the geometrical design of the inlet and outlet, and serially connecting one to several buffer chambers to the micropump in order to discuss its influence on the flow resistance and the pumping efficiency. Besides flow rate, by comparing the simulation flow field with experimental results in order to have more detailed explanation of the flow mechanism.
Unlike the commonly used method of simulated micropump, the pumping performances of a piezoelectric valveless micropump are investivated in terms of the three-dimensional electro-fluid-structural interaction. General CFD software processing fluid-structure interaction using moving boundary method. However, this paper using two-way direct FSI. ANSYS and ANSYS CFX are used for the structural and fluid domains, respectively. Both the structural and fluid domains are coupled in the three-dimensional simulation. The flow field calculated by synchronous two-way coupling is closer to reality than the moving boundary.
The numerical results showed that the flow rate increased substantially when radius for the inlet and outlet was 1.2 times of the chamber. Despite the numerical results are not accurate enough, the trends of simulation roughly match the experimental results. In addition, numerical results also showed the design of buffers can really enhance the performance of micropump, especially the design of each buffer serially connecting on the both sides of the chamber is optimal. These simulations are also consistent with the experimental results.
The flow visualization analysis shows that the best pumping efficiency happened as the vortex pairs of inlet and outlet region and the vortex pair in the vibrating chamber near the outlet diffuser reached maximum. The flow field of simulation also presents similar trends. Consequently, “varying the size of inlet and outlet” and “buffers serially connecting to a vibrating chamber” both could decrease the flow resistance and provided enough space to make the vortex inside chamber develop well. Hence, the micropump performance is obviously enhanced.
Subjects
PZT valveless micropump
FSI numerical simulation
size of inlet and outlet
buffers
Type
thesis
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