Successful PhD at FST: Dynamic characteristics of annular gaps with an axial flow component

On 17 March 2022, Dr.-Ing. Maximilian Kuhr successfully defended his doctoral thesis on “Dynamic characteristics of annular gaps with an axial flow component”.

The main focus of his research at the Chair of Fluid Systems (FST) is the calculation and experimental identification of the induced motion-dependent forces and torques of turbulent annular gap flows on a rotor, as they occur, for example, in media-lubricated journal bearings and contactless annular seals.

Here, the intention is to characterise these dynamic forces and torques with the help of rotordynamic coefficients in the form of classical mechanical elements, creating a link between the disciplines of rotordynamics and fluid mechanics. In contrast to the currently common modelling based on purely translational movements, the rotational degrees of freedom are also taken into account.

The results lead to an improved understanding of the dynamic characteristics of annular gaps and thus to an improved understanding of the dynamic influence of the annuli on the dynamic behaviour of modern turbomachinery. This improved understanding, coupled with the numerical and experimental database, makes it possible to push the performance limits of existing and future machines and thus contribute to more sustainable development.