A partitioned solution approach for the fluid-structure interaction of thin-walled structures and high-Reynolds number flows using RANS and hybrid RANS-LES turbulence models

Abstract

In this work the partitioned solution approach for the fluid-structure interaction (FSI) of thin-walled structures and high-Reynolds number (Re) flows modeled using Reynolds-Averaged Navier-Stokes (RANS) and hybrid Reynolds-Averaged Navier-Stokes - Large Eddy Simulation (RANS-LES) turbulence models are described. The advanced turbulence modeling is needed to capture very complex fluid phenomena which triggers instabilities of thin-walled structures present in supersonic flow regimes. The finite element (FE) updated Lagrangian formulation (ULF) for the nonlinear elastic solids is used to predict its dynamical behavior. The main contribution addresses to the linear stress-strain relation Laplacian members, which are solved implicitly, on that way decreasing required memory resources and improving solution stability in the same time. The structures of the interest include the vast variety of membranes, curved shells and plates. The instabilities encountering these structures include limit cycle oscillations (LCO), flutter and buckling of the panels. The phenomena appear in everyday engineering practice and a need for the powerful tools to handle such problems is a common goal. Utilization of the unstructured non-regular meshes allows the precise distribution of computational nodes at the physical boundaries of the fluid and solid domains. It is naturally allowing application of the common approach for the fluid-solid interface coupling, as well as classical data interpolation schemes between fluid and solid on the FSI interface. High-Re flows, both 2D (benchmark) and 3D turbulent FSI case are chosen for the validation. Two numerical methods are coupled via a moving boundary treatment, in a staggered way. The proposed coupling method showed a good agreement with the reference test cases. The current FSI framework is developed to serve as a tool for the liquid rocket engine development.