We are on the EnginSoft Newsletter Year 18 n.4 Winter!

Our study Using high-fidelity FSI simulation and advanced mesh morphing to simulate and mitigate vortex-induced Vibrations discusses the complex and challenging problem of controlling vortex-induced vibrations (VIV). The fluid structure interactions (FSI) involved pose two types of problems: firstly, structural and fluid analysis skills are required and the various experts need to interact correctly for a successful outcome; secondly, accurate modelling requires state-of-the-art tools to combine the computational fluid dynamics (CFD) and the computational structural mechanics (CSM). Advanced mesh morphing enabled by the radial basis function (RBF) is key here: it enables you to create an efficient and fast workflow for strong coupled fluid structure interaction analysis while making that workflow parametric with respect to the design, so that you ultimately have the ability to steer the design toward the desired VIV behavior. We used structural modes embedding technique to render the fluid solution “flexible”. The dynamic characteristics of the system were calculated with Ansys Mechanical for the Finite Element Analysis (FEA); these were then incorporated into Ansys Fluent to solve the fluid aspect using RBF Morph mesh morphing software. The method is demonstrated for a specific application: the design of a thermowell immersed in a water flow. The numerical results obtained were compared with experimental data and showed a satisfactory agreement, thus demonstrating that the superposition of structural modes approach, with a suitable mesh morphing configuration, is able to address unsteady FSI problems with the necessary accuracy for industrial applications.

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