Strongly coupled flow/structure interactions with a geometrically conservative ALE scheme on general hybrid meshes

Abstract

A geometrically conservative finite-volume arbitrary Lagrangian–Eulerian (ALE) scheme is presented with general hybrid meshes. A moving mesh source term is derived from the geometric conservation law and physical conservation laws on arbitrarily moving meshes. The significance and effectiveness of the moving mesh source term regarding uniform flow preservation is demonstrated and also compared to a different ALE formulation without such a source term. The temporal accuracy of the current ALE scheme does not deteriorate with the use of moving meshes. The applicability of the presented ALE scheme is demonstrated by simulating vortex-induced vibrations (VIV) of a cylinder. Two different flow–structure coupling strategies, namely weak and strong, are employed and compared. The proposed strong coupling is implemented with a predictor–corrector method, and its superior stability and time accuracy over weak coupling schemes is demonstrated. The present scheme can employ general hybrid meshes consisting of four different types of elements (hexahedra, prisms, tetrahedra and pyramids) and yields good agreement with other computational and experimental results.