Domain Preparation For Ranse Simulations About Hull And Appendage Assemblies

Viscous flow simulations are increasingly employed for simulation-driven design of functional surfaces. While parametric modeling of complex shapes has reached a certain maturity, the transfer of data from the Computer Aided Design (CAD) model to the Computational Fluid Dynamics (CFD) code is non-trivial unless the shapes are topologically simple. Assemblies of hull and appendages, however, usually require manual preparation. A method will be presented that allows setting up watertight compositions of arbitrary shapes. The method was implemented within the CAD-CFD integration platform FRIENDSHIP-Framework. Closed surfaces are subdivided into irregular triangle meshes (trimeshes) of predefined tolerance, i.e. deviation allowed between the original shape and its finite approximation. Solids can then be made from the trimeshes. Assemblies of hull and appendages can thus be realised supporting Boolean operations. An STL-file export is offered to connect to grid generators such as HEXPRESS and SnappyHexMesh. The method automatically copes with changes in shape by means of parametric modeling. The paper elaborates on the algorithms and presents examples.