The aim of the sub-project is the further development and application of hybrid simulation methods for the determination of loads on energy saving devices (ESD), in particular pre-swirl ducts (PSD), under off-design conditions. The first aim is to improve the accuracy of the hybrid URANS-LES method for smooth water resistance prediction. For this purpose, the hybrid model is only used in the stern of the ship, where strong vortex structures are to be resolved, while the pure URANS method, which reflects the frictional shear forces well, is used for most of the ship's length. The hypothesis of a fully turbulent flow around the PSD/ESD will be tested with a transition model. The crash-stop manoeuvre and the behaviour in rough seas are investigated as off-design conditions. The flows with overset grids (also known as overlap grids) are analysed numerically and the hybrid method must be made robust for the use of this method. In particular, this concerns the development of a solution for the smooth change of the turbulence-determining transport variables within the overlap zones. Based on the hydrodynamic calculations, a database of the forces for the structural-mechanical evaluations of the ESD under off-design conditions will be created.