Minimization of undesired wave reflections at the boundaries of the computational domain in flow simulations with free surface based on the Navier-Stokes equations

• Applicant: Professor Dr.-Ing. Moustafa Abdel-Maksoud
• Subject Area: Fluid Mechanics
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 321791315

The ability to accurately simulate the propagation of free surface waves and the corresponding fluid-structure-interactions are important topics in computational fluid mechanics, especially in regards to maritime industry and research. The main difficulty in applying RANSE-based simulation techniques is minimizing undesired wave reflections at the boundaries of the computational domain, since such reflections can lead to considerable uncertainties in the simulation results. By introducing source terms into the governing equations within a zone in the vicinity of the domain boundary, outgoing waves can be damped. Another way to reduce wave reflections is to couple the RANSE solver with a second flow solver. In this case, the RANSE solution can be blended to the solution of the other flow solver. Within the current state of knowledge, selecting the optimum source terms is a problem which remains insufficiently investigated. Hence, the main aim of this research project is to develop adaptive approaches for minimizing undesired wave reflections. In this case, the source terms will be adjusted with respect to incoming waves so that they are set to their optimum values at all times during the simulation. The developed approaches will minimize undesired wave reflections and enable prediction of the corresponding uncertainties before starting the simulation. After sufficient validation for 2D and 3D simplified cases, the applicability of the developed methods will be demonstrated for typical three-dimensional maritime flow simulation problems.

• DFG Programme: Research Grants