In an effort to provide accurate simulations of fluid-structure interactions in turbomachinery, this paper describes a powerful method to deform mesh, using interpolation based on radial basis functions (RBF). It has been assessed on a 3D annular turbine, including a tip gap. The main difficulty of this method is to define number and position of control points. A greedy algorithm is proposed to address this issue and is tested on the annular turbine and a deforming panel placed in a shock tube. Finally, the method is slightly adapted to take into account periodic boundary conditions, which allow mesh morphing for a unique interblade channel by preserving constant pitch on lateral boundaries.

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The prediction of FSI limit cycles involving transonic separated flows requires efficient and accurate solvers coupling techniques. Explicit partitioned strong coupling is considered in time domain, where careful attention should be paid to energy conservation at the fluid-structure interface. For all the presented results, both meshes are set up such that structural skin points and fluid boundary mesh points are collocated. The presented test case involves a shock tube in which the shock wave impinges on a cross flow flexible panel, initially at rest. Compared to experimental results, the pressure peaks and fluctuations are correctly predicted but the pressure level is over predicted as well as the displacement frequency. Results analysis explains correctly the flow physic which is shown to be weakly modified by structural damping, turbulence modeling and time discretization. This discrepancy between experimental and numerical results could been explained by the structure model, in which the panel root modeling might be questionable.