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SC²S Colloquium - July 11, 2018

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Date: July 11, 2018
Room: 02.07.023
Time: 15:00 - 15:30

Benjamin Rüth: High-Order Time Stepping in Partitioned Fluid-Structure Interaction with Black-Box Solvers

This is a wccm18 conference talk preview submitted as

  • High-Order Time Stepping in Partitioned Fluid-Structure Interaction with Black-Box Solvers by Benjamin Rüth, Benjamin Uekermann, Miriam Mehl, Hans-Joachim Bungartz

Fluid-structure interaction problems are solved by applying either the monolithic or the partitioned approach [1]. While the monolithic approach usually provides more stable solutions, the partitioned approach has many advantages from a software engineering perspective as, for example, the reuse of well-tested existing solvers (participants) in a black-box fashion. However, this typically results in a degradation of time stepping to first order if applied in the standard way [2] - even if the used solvers are of higher order.

In this talk, the convergence order of time-stepping for a simple 1D model problem is investigated. In our partitioned approach, the solvers are considered as black-boxes: Only nodal data at the wet interface between the fluid and the structure region is exchanged between the solvers. The aforementioned effect of order degradation is reproduced for state-of-the-art explicit (weak) and implicit (strong) coupling. Finally, an order conserving coupling scheme is introduced. This scheme allows to couple participants using arbitrary time stepping schemes and differing temporal meshes.

In the future, we plan to implement this mechanism in the open source coupling library preCICE [3] to be able to solve complex multi-scale-multi-physics scenarios, such as turbulent fluid-structure interaction or fluid-structure-acoustics interaction. Currently, very small time steps are needed in this area due to degradation of convergence order and stability properties of the time-stepping scheme if a partitioned approach is in use.

References

[1] C Michler et al. "A Monolithic Approach to Fluid-Structure Interaction". In: Comput. Fluids (2004)

[2] C. Farhat and M. Lesoinne. "Two efficient staggered algorithms for the serial and parallel solution of three-dimensional nonlinear transient aeroelastic problems". In: Comput. Methods Appl. Mech. Eng. (2000)

[3] Hans-Joachim Bungartz et al. "preCICE - A fully parallel library for multi-physics surface coupling". In: Comput. Fluids (2016)

Keywords: Fluid-structure interaction , preCICE, Time integration