Three-dimensional fluid-structure interaction simulation with a hybrid RANS-LES turbulence model for applications in transonic flow domain

Abstract

Current industrial practice for the fluid-structure interaction (FSI) analyses and prediction of aeroelastic phenomena, such as flutter, is heavily based on linear methods. These methods involve many of design limitations and envelope restrictions for aircraft. In this paper novel hybrid Reynolds-Averaged Navier-Stokes - Large Eddy Simulation (RANS-LES) turbulence model, i.e. k-Omega Shear Stress Transport Scale-Adaptive Improved Delayed Detached Eddy Simulation (k-Omega SST SA IDDES) is tested and implemented in the FSI procedure and is applied in transonic flow. This model is also compared with the lower fidelity RANS models, i.e. k-omega SST and Spalart-Allmaras. More precisely, a strongly coupled three-dimensional (3D) PSI solver is combined with the turbulence model and large deformation updated Lagrangian finite volume structural solver in order to resolve standard computational fluid dynamics (CFD) and aeroelastic benchmark cases of transonic flow. The turbulence model combines the advanced capabilities of the existing SST, SAS and IDDES turbulence models. Unsteadiness detection deficiency of SAS is automatically supplemented by the IDDES term included in kinetic energy equation. The numerical results of Onera M6 and AGARD 445.6 validation cases are presented and compared with the existing experimental results. Discretization of the governing equations is performed by cell-centered finite volume method (FVM) on unstructured meshes. Further application of the FSI procedure for the FSI analyzes of the whole aircraft structures is one of the aims. The emphasis is made on turbulence modeling which appears to have a major impact to the prediction of FSI behavior in transonic flow domain. In this work the aeroelasticity is treated as one of the many FSI branches. Described FSI solver is custom written and implemented in OpenFOAM.