Publication in the Journal of Tribology

Most studies today focus only on the dynamic properties due to translational motions, while the tilting and moment coefficients are less well studied. In order to assess whether the hydraulic tilting and moment coefficients need to be considered during the turbomachinery design process, the authors define an effective stiffness, which can be used to show that, in addition to the annular gap length, the flow number and a modified Reynolds number are crucial for the relevance of the additional coefficients. This leads to a simple three-dimensional diagram, which makes it possible to assess the necessity of including the additional coefficients on the basis of the three variables.