Multiscale adaptive methods for fluid-structure interaction (DLR.6755)

Computational methods for simulating the interaction between a flexible structure and an adjacent fluid (liquid or gas) flow are of critical importance in many engineering disciplines. Paradoxically, such fluid-structure-interaction problems elude current computing capabilities on account of the complexity of the subsystem that is of least practical interest, viz., the fluid. The resolution of each of the many small-scale features in the fluid is prohibitive. However, practical interest is generally restricted to the structural response.

Optimal-adaptation strategies provide a paradigm to bypass this paradox.
The crucial point is that to determine the structural response, it is not generally necessary to resolve all the small-scale features in the fluid. Many features can be represented by a simple model or even be neglected, without essentially degrading the accuracy of the prediction of the structural response. In an optimal-adaptation methodology, a sensitivity indicator can be constructed to identify the contribution of local errors in the small-scale features of the fluid to the error in the global structural response. Only the small-scale features that have a pronounced influence on the structural response need to be resolved.

The objective of the proposed research is to develop optimal-adaptive computational techniques for fluid-structure interaction.
Two complementary aspects are considered, viz., adaptive discretisation methods and adaptive multiscale modelling of turbulent flows. It is anticipated that these techniques can significantly reduce the computational cost of fluid-structure-interaction problems, thus rendering complex problems for practical applications amenable to current computing capabilities.