DEVELOPMENT OF IMMERSED BOUNDARY METHOD FOR FLUID-STRUCTURE INTERACTION AND ITS APPLICATION

Abstract

Within the framework of the diffuse interface immersed boundary method (IBM), this thesis proposes several efficient numerical approaches for simulating isothermal and thermal fluid-structure interaction (FSI) problems. Firstly, two novel coupling approaches of the explicit boundary condition-enforced IBM integrated with the reconstructed lattice Boltzmann flux solver (RLBFS) and the reconstructed thermal lattice Boltzmann flux solver (RTLBFS) are developed to simulate isothermal and thermal FSI problems with large deformations and complex geometries, respectively. Secondly, a novel explicit boundary condition-enforced IBM for Neumann boundary conditions is proposed, which circumvents the needs to assemble a large correlation matrix and inverse it in the original implicit scheme. Thirdly, a novel implicit boundary condition-enforced IBM for Robin boundary conditions is proposed, where the Robin boundary condition is found to be accurately enforced. Based on the developed methods, the hydrodynamic performance of a carangiform swimmer is investigated, revealing some novel scaling laws.