This article gives an overview of the results of the wind energy research project AssiSt. Results of the four work packages include flow in complex terrain, wind energy converters (WEC) in complex terrain subject to atmospheric inflow, laminar-turbulent transition, generator cooling, hub aerodynamics, and passive flow control devices. Four different flow solvers (PALM, FLOWer, THETA, OpenFOAM) are in use during the course of the project depending on the corresponding problem requiring specific solver features. Key achievements of the project are the coupling of atmospheric LES (PALM) and URANS simulations of the complete WEC (FLOWer as well as THETA) in order to impose the external turbulent flow fields to the inflow of the WEC for physics resolved load simulations, numerical replication of complex flows over blades with vortex generators using OpenFOAM and efficiency-augmented pressure loss simulations on very complex industrial geometries of ENERCON's direct drive WEC generators for precise cooling analyses. Industrial validity of all methods, model and process developments were key objectives of this research project.