Adaptive grid refinement for hydrodynamic flows

An adaptive grid refinement method is presented for hydrodynamic flow simulation. It is meant for application to a wide range of realistic flow problems, so generality and flexibility of the method are essential. Directional refinement is developed to be used with unstructured hexahedral meshes, tensor-based refinement allows the implementation of many different refinement criteria. Good grid quality is assured by creating buffers of refined cells around relevant flow features. Tests are performed with two refinement criteria, based on the free surface and the Hessian matrix of the solution respectively; these show great increases in efficiency with respect to non-refined grids.

► We present a powerful grid refinement method for complex, realistic flow simulation.
► For unstructured hexahedral grids, anisotropic grid refinement is mandatory.
► Metric tensors allow the most robust and flexible control of anisotropic refinement.
► Unstructured grids demand a high precision in the computation of refinement criteria.
► Demanding test cases from marine hydrodynamics show important gains in efficiency.