报告人： Prof. Jie Li
An Arbitrary Lagrangian Eulerian Method for Moving-Boundary Problems
In this talk, we present an ALE (Arbitrary Lagrangian Eulerian) moving mesh method suitable for solving two-dimensional and axisymmetric moving-boundary problems. Our method employs a body-fitted grid system where the gas-liquid interface and solid-liquid interface are lines of the grid system, and complicated dynamic boundary conditions are incorporated naturally and accurately in a Finite-Volume formulation. The resulting non-linear system of mass and momentum conservation is then solved by a fractional step (projection) method. The method is validated on the uniform flow passing a cylinder (a two-dimensional flow with a solid structure) and several problems of bubble dynamics (axi-symmetrical flows with a free surface) for both steady and unsteady flows. Good agreement with other theoretical, numerical and experimental results is obtained. This work is part of our effort to incorporate complicated physics involving moving boundaries in a general and flexible framework. We have included abilities such as handling the interaction between a free-surface and a solid structure, a viscoelastic fluid and the Marangoni effect induced from a surfactant. Our method is applied to the investigation of a two-dimensional mechanical strider (a mass-spring system) interacting with a water surface, and the bubble dynamics in a surfactant polymeric solution.
报告时间： 2006年6月19日(周一) 下午3:30--4:30