This contribution is dedicated to demonstrating the high potential and manifold applications of state-of-the-art computational fluid dynamics (CFD) tools for free-surface flows in civil and environmental engineering.All simulations were performed with the academic research code ELBE (efficient lattice boltzmann environment, http://www.tuhh.de/elbe). The ELBE code follows the supercomputing-on-the-desktop paradigm and is especially designed for local supercomputing, without tedious accesses to supercomputers. ELBE uses graphics processing units (GPU) to accelerate the computations and can be used in a single GPU-equipped workstation of, e.g., a design engineer. The code has been successfully validated in very different fields, mostly related to naval architecture and mechanical engineering. In this contribution, we give an overview of past and present applications with practical relevance for civil engineers. The presented applications are grouped into three major categories: (i) tsunami simulations, considering wave propagation, wave runup, inundation and debris flows; (ii) dam break simulations; and (iii) numerical wave tanks for the calculation of hydrodynamic loads on fixed and moving bodies. This broad range of applications in combination with accurate numerical results and very competitive times to solution demonstrates that modern CFD tools in general, and the ELBE code in particular, can be a helpful design tool for civil and environmental engineers.

This contribution addresses the applicability of an efficient lattice Boltzmann-based single-phase free-surface model for the simulation of wave impact on the side walls of 2-D containers. The computational efficiency of the method is known to allow for very short turnaround times, but wave impact simulations have not been investigated in detail yet. Results for a selected wave impact case are discussed, the convergence behavior in space and time is analyzed, and limitations of the single-phase free-surface model are revealed. The results show that lattice Boltzmann method (LBM)-based single-phase free-surface models are a viable tool for predicting the impact wave behavior, but the quality of the pressure signal is limited, because of the absence of air in the simulations.