Integrating Finite Element and Optimization Software for Shape Optimization: A Micropump Design Case Study

This thesis explains the process of simulating a two dimensional micropump that includes integrated components using multi-physics finite element analysis software. This thesis is an exploration of how a micro-pump should be modeled for optimization using multi-physics finite element software, not an exploration of what an optimally designed micro-pump would look like. A micropump is a device used to pump micro amounts of fluid. Due to its accuracy and a wide variety of applications, micropumps are becoming more popular to the researchers and manufacturers. Depending on the applications and mechanisms used, there are many different kinds of micropump available on the commercial market. In this case study, the micropump has an oscillatory diaphragm that causes a pressure difference in a pumping chamber that creates fluid flow controlled by valves. The diaphragm is actuated by applying electrical energy to lead-zirconate-titanate (PZT) that is transformed into elastic deformation that causes volumetric displacement inside the pump chamber.;This thesis also explains how the performance of the micropump can be optimized by varying the geometry of the micropump. Geometry coordinates have been considered as a set of variable parameters which can create any shapes within the range. A line search optimization method has been used to maximize the outlet flow and pressure of the micropump. In this method, the optimization subroutine sends a set of coordinate parameters that creates a new geometry in the finite element software, meshes and evaluates a performance function which is then fed back to the optimization subroutine for the next function call.;This thesis also explains how a nonlinear and complex system can be optimized by applying non linear constraints such as a minimum pressure constraint at the outlet. This thesis is useful to many areas of design, where not only the product but its efficiency is important. The approach demonstrated is useful when considering any finite element parameter that can be optimized, providing greater flexibility in modeling and designing physical objects and for design validation.;This thesis will explain how an oscillatory valve micropump can be modeled, simulated and optimized using finite element and optimization software. The two dimensional dynamic nonlinear model involves many different application modes such as the Navier-Stokes and piezo plane strain equations. The geometry, solid-liquid interactions, and moving boundaries make the model complex to solve analytically. Commercially available multi-physics finite element software has facilitated the development of the micropump model with its capability of creating scripts of the model that could be run under external optimization program control.