F. G. Di Vincenzo
DOI Number: N/A
Conference number: IFASD-2019-110
A seamless coupling interface called HFSI, has been developed to enable connecting MSC Nastran SOL 400 [1] to any mesh-based CFD solver with all element topologies to allow for efficient and accurate fluid-structure interaction simulation both steady and unsteady. The novel interface enhances a recently developed approach [2] with a new user interface, a novel user defined DMAP module [3, 4], UDMSRV, developed to give a direct access to data from CFD by means of an extended Interface Definition Language (IDL). A new Nastran SubDMAP [3, 4] called SPLINE, that exchanges data with the CFD through the UDMSRV module, has been implemented in the HFSI interface to perform the interpolation at the aero-structure interface and carry out the morphing of the CFD domain. Two different morphing algorithms have been implemented in the SPLINE module. The first one is an enhancement of a method based on the FEM analogy presented in a previous work [2] that has been improved to take care of polyhedral mesh. The second one, here called FEMRIS, is a new hybrid approach developed to combine the fastness of Radial Interpolation Spline (based on Radial Basis Functions), with the accuracy and robustness of the FEM analogy. The latest shows promising results with full scale models where both accuracy and efficiency are important. Sliding and stiffness features have been also added to the morph algorithm to improve the quality and efficiency of the CFD domain deformation. The new coupling approach here presented, where Nastran computes the interpolation at the aero-structure interface and morphing of the CFD domain, really improves the performances of the simulation and robustness of the morphing and thanks to the additional aerodynamic IDL it opens the application to any suited CFD solver. The scope of this work is to illustrate the advantage and benefit of employing such a methodology to real cases and understand the versatility of such an architecture that can be easily extended to any FEM and CFD solvers different from those proposed in the present work. CFD solvers from Cradle [5], that use both tetrahedral and polyhedral mesh, have been chosen for this activity. A transient fluid-structure interaction simulation will be presented: Supersonic nonlinear panel flutter.