Minimizing undesired wave reflection at the domain boundaries in flow simulations with forcing zones

1 Introduction Key findings • In flow simulations, undesired wave reflections at domain boundaries can produce significant errors • An overview over techniques to reduce such undesired reflections is given • Forcing zones can reduce undesired reflections by applying source terms in the vicinity of domain boundaries, but contain case-dependent parameters • In this thesis, an analytical approach is developed to optimally tune the case-dependent parameters of forcing zones • This work focuses on finite-volume-based flow simulations with free-surface waves for typical ocean engineering and shipbuilding applications • Further, (hydro-)acoustic flow simulations will be performed as a computationally efficient model of shallow water waves In flow simulations, it is usually desired to choose the computational domain as small as possible to reduce the computational effort. Thus when simulating free-surface wave propagation, undesired wave reflections at the domain boundaries must be minimized. If this is not achieved, the reflections travel back into the solution domain and can lead to large errors in the results. For finite-volume-based flow solvers there are many unresolved problems, especially – reliable reduction of reflections at the domain boundaries, – prediction of the amount of undesired wave reflection before performing the simulation. This work aims to provide further insight to solve these problems for flow simulations based on Navier-Stokes-type equations (Reynolds-averaged Navier-Stokes (RANS), Euler equations, Large Eddy Simulations (LES), etc.) discretized via the finite volume method. In Sect. 1.1, different techniques to reduce undesired wave reflections at domain boundaries are compared. Subsequently, the aim of the present thesis is outlined in Sect. 1.2, followed by an overview of the thesis structure in Sect.