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Center for Nonlinear Studies |
Isogeometric Analysis (IGA) is finite element based tool that can be used to simulate complex fluid mechanics and structural mechanics. This approach uses Non-Uniform Rational B-Splines (NURBS) as the basis functions for finite element analysis. This presentation focuses on the use of IGA to solve two difficult problems, the modeling of a Pulsatile Ventricular Assist Device (PVAD), and shock hydrodynamics. PVADs are medical devices used to assist a single ventricle of a failing heart. They are mechanical displacement pumps that are difficult to model with conventional numerical tools due to a highly non-linear thin membrane structure which exhibits large deformations and buckling. We present a Fluid-Structure Interaction (FSI) framework that allows for the simulation of these devices under normal physiologic operation for the first time. The device consists of a blood chamber and an air chamber, with a thin membrane divider. The membrane is modeled using IGA with a Kirchhoff- Love shell solver to solve the membrane mechanics. The two fluid domains are solved using an Arbitrary Lagrangian Eulerian (ALE) finite element framework. Methods for the coupling between fluid and structure are also presented. IGA is also used to model fluids directly, and its application to the classic Noh and Sedov problems in a Lagrangian framework is presented.
Host: Misha Shashkov