The artificial added mass effect in sequential staggered fluid-structure interaction algorithms

The artificial added mass effect inherent in sequentially staggered coupling schemes is investigated by means of a uid-structure interaction problem. A discrete representation of a simplified added mass operator in terms of the participating coefficient matrices is given and `instability conditions' are evaluated for different temporal discretisation schemes. With respect to the time discretisation two different cases are distinguished. Discretisation schemes with stationary characteristics might allow for stable computations when good natured problems are considered. Such schemes yield a constant instability limit. Temporal discretisation schemes which exhibit recursive characteristics however yield an instability condition which is increasingly restrictive with every further step. Such schemes will therefore definitively fail in long time simulations irrespective of the problem parameters. It is also shown that for any sequentially staggered scheme and given spatial discretisation of a problem, a mass ratio between uid and structural mass density exists at which the coupled system becomes unstable. Numerical observations confirm the theoretical results.     «

The artificial added mass effect inherent in sequentially staggered coupling schemes is investigated by means of a uid-structure interaction problem. A discrete representation of a simplified added mass operator in terms of the participating coefficient matrices is given and `instability conditions' are evaluated for different temporal discretisation schemes. With respect to the time discretisation two different cases are distinguished. Discretisation schemes with stationary characteristics migh...     »