新聞標題： ( 2019-09-25 )
演講主題：An strongly-coupled immersed-boundary formulation for rigid-bodies interacting with fluid flow
演講日期：2019 年10月1日(星期二) 13:20 –14:20
摘要內容：We present a strongly-coupled immersed-boundary method for flow–structure interaction problems involving rigid bodies. The method is stable for arbitrary choices of solid-to-fluid mass ratios and for large rigid-body motions. Dynamics of rigid bodies is characterized by the velocity of the center of mass and the angular velocity about the center of mass, which are governed by the translational and rotational equations of motion involving boundary forces. By introducing the summation and distribution operators, equations of motion are coupled with the incompressible Navier-Stokes equations through the no-slip constraint and boundary forces. Boundary forces are regarded as Lagrange multipliers that enable the no-slip constraint to be implicitly determined to arbitrary precision without associated time-step restrictions. Through projections, the current method removes not only slip component of the velocity field but also components of rigid-body dynamics that do not satisfy equations of motion. We verify our method by simulating the free fall of a circular cylinder and further apply our method for investigating the starting of a flow-driven vertical-axis wind turbine.