Finite Element Analysis with Immersed Boundary Method for Fluid-structure Interaction Problems

• Main Authors: Chia-Lin Chiu, 邱家麟
• Other Authors: 楊德良
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/40940202710627046271

博士 === 國立臺灣大學 === 土木工程學研究所 === 94 === The thesis is concerned with developing a finite element procedure based on the immersed boundary technique to allow the numerical investigations of the interaction between the flow and the moving objectives. Such a developed model must be composed of a reliable and efficient flow solver, capability of handling the complex geometry and moving boundary, as well as accurate prediction of the fluid force acting on the moving objective. For establishing the flow solver, the mixed order formulation and operator splitting scheme are first presented for solving the primitive variable form of the Navier- Stokes equations. Next, the unstructured element and the structured gird with immersed boundary technique are respectively employed for dealing with the complex geometry. As far as the moving boundary is concerned, we develop a hybrid Cartesian/immersed boundary model with a robust interpolation scheme, and further propose a novel methodology including a moving grid process to reduce the numerical diffusion near the immersed boundary. Finally, the moving grid process is improved for accurately calculating the fluid force acting on the moving objective so as to describe the fluid-structure interaction problems. All the numerical results are compared favorably with the reference data, and several interesting phenomena, such as lock-in behavior, are well captured by our developed model.