Fast and Robust CFD Simulation Method for Water Management in Automotive Interior Design

Knowledge of the behavior of fluid flow over and into narrow gaps is important in many industrial applications, particularly in the automotive sector. Evaluating the potential of water entering narrow pathways and towards components that can be damaged by it is of great importance. CFD simulations can help in evaluating the potential of water getting into such gaps. Meshless tools are used in a variety of simulation scenarios of fluid flow, especially due to their ability to easily simulate free surfaces with strong curvatures. In previous work, a validated simulation setup was created in the meshless simulation tool Meshfree from Fraunhofer ITWM for simulating water entering in small gaps. Currently, the simulation time of the setup needs to be sped up especially for industrial use cases, where simulation times higher than 6-10 days were encountered. Because of these long simulation times a fast and robust CFD simulation method was developed to be able to simulate even industrial use cases in an appropriate time (<5 days). The development of the fast and robust CFD simulation method was done in two stages. First the previous validated simulation method was taken and different parameters (e.g. parameters influencing time step sizes) were tested in a simplified benchmark case for their influence on time and robustness. Secondly the most promising parameter setup was taken and further optimized regarding simulation time and robustness for an industrial use case. The results showed high potential in reducing the simulation time necessary. The findings will be used and improved in further work regarding water pathways in a vehicle's interior.