Topology optimization method applied to flow machine rotor design working in laminar flow

Abstract

This work is part of the thematic project "Sistemas Propulsores Eletromagnéticos para Coração Artificial Implantável e Dispositivos de Suporte Circulatório Mecânico", Fapesp number 2013/24434-0. One of the project topic is ventricular assist devices (VAD), thus, thus, this work aims to optimize the performance of small scale pump impellers that are used as VADs. These devices are implanted in high risk patients. Thus, the performance and reliability are of fundamental importance, and small performance gains can cause big benefits for the patient life. Performance improvements can be achieved by using optimization methods, such as topology optimization. This work aims to develop a method to design a flow machine's rotor that works on laminar flow, based on topology optimization method. The design of a rotor involves modeling the fluid flow by using Navier-Stokes equations on a rotary referential. This will be done by using the OpenSource software FeniCS. The modeling of the optimization problem presents a multi-objective function aiming to minimize the pressure loss caused by viscous dissipation, vorticity and power, with volume constraints that limit the solid-fluid relation on domain. This problem will be implemented using DOLFIN-adjoint platform and the PyIpopt optimizer. The resulting topologies will be built by using a 3d printer an experimental characterization is performed by measuring fluid flow and pressure head. Design for rotors of bi-dimensional radial flow machines of small scale that work in laminar flow, aiming to use them in ventricular assist pumps, and also the experimental comparison between prototypes will be presented as results. (AU)