Calculating rotordynamic coefficients of liquid annular seals by CFD for vibration analysis and validation at the test rig

This article presents a simulation methodology for calculating rotordynamic coefficients of liquid annular seals using the open source software OpenFOAM. Therefore, stationary fluid solutions for several boundary conditions are generated to represent the rotational shaft speed, the eccentricity and the whirling motion. Analyzing the acting forces in a whirling coordinate frame leads to a simple curve fit to determine the rotordynamic seal coefficients. The CFD approach is validated with an analytical solution and the coefficients of characteristic states are compared to literature results. Finally, the methodology is applied to our test rig’s geometry to calculate its dynamic behavior. The comparison between the simulated and measured behavior shows good agreement.