A structured mesh boundary motion approach for simulating wind effects on bluff bodies with changing boundaries

In a number of computational fluid dynamics based wind engineering applications the possibility to move the boundary of the structure without having to re-mesh the computational domain represents a significant computational advantage. Examples of such applications are aerodynamic shape optimization, mesh generation around complicated geometric forms and simulations around bodies with time dependent rigid/deformable boundaries. Strategies for solving this type of problem have been widely investigated in both a general context—e.g. dynamic mesh, adaptive mesh refinement or embedded boundary method—as well as more specific cases such as aerospace applications and fluid–structure interaction problems. This paper focuses on developing an efficient method for morphing the kind of structured meshes often encountered in civil engineering applications that are characterized by complicated bluff bodies. In particular a coupled parametric user-defined boundary motion and dynamic mesh approach is proposed specifically for solving fluid simulation problems around such bodies. The method is focused on providing an efficient means for updating structured wall clustered boundary meshes, important for reliable turbulent flow simulations, where the aim is the estimation of the effects of small/local deformations of the boundary. A novel algorithm is also developed to protect/repair the mesh during boundary motion when folding, and therefore loss of mesh validity, is likely to occur. The effectiveness of the proposed approach is demonstrated on a number of structural engineering applications such as turbulent flows around chamfered corners of tall buildings, rapid mesh generation around geometrically more involved bluff bodies and forced oscillations of bridge decks.