Ass.-Professorship Fluid-Structure Interaction in Multibody-Systems
The dimensioning of mechanical systems under the influence of dynamic loads is a central point of the design process of complex machines. In the context of increasing loads, the omnipresent trend towards lightweight constructions and continuous optimisations the importance of studies with a high level of detail concerning the transient behaviour of the system rises. As a result, additional field problems, which interact with the structural properties, must be taken into account to exploit potential reserves and allow technical progress.
The field of fluid-structure interaction the coupled behaviour of the overall system is analysed taking into account the non-linear interactions between mechanical structure and the influencing fluid (for general transient loading and spatial movement a modelling approach of the mechanical properties using multibody-approaches is useful).
One focus is set on the modelling of hydrodynamic bearings (journal bearings, thrust bearings, floating-ring bearings), whose behaviour are per se non-linear and can lead to potential instabilities. Therefor, the governing equations of the fluid (Reynolds differential equation as well as energy equation), the equation of motion of the mechanical system (represented both by rigid and/or flexible bodies) and the non-linear interactions between both field problems, which influences each other, have to be solved - in most cases using numerical approaches.
Due to the holistic description, non-linear vibration effects (such as oil-whirl, oil-whip or genearal sub- and super-harmonic vibrations) can be investigated in detail to analyse the influencing parameter, to predicted resulting vibration amplitudes and frequencies, and to develop countermeasures finally.