F3 - Rotordynamic Fluid Forces
and Moments from Bearings, Seals
and other supporting structures

Organizers: D. Kim & A. Dadouche

Daejong Kim is currently an associated professor at University of Texas at Arlington. He obtained his BS and MS at Seoul National University in 1991 and 1993 respectively, and PhD at University of Texas at Austin in 2004. Areas of research are fluid film bearings, gas bearings, rotordynamics, energy system integration.

Azzedine Dadouche is a Research Officer at the National Research Council of Canada. His main research interests are topics related to hydrodynamic lubrication, rotor-bearing systems performance as well as bearing and gear health condition monitoring.


Various rotor vibration problems caused by the increase of energy density occur on rotating machineries frequently. Such problems are the result of the interaction between excitation and damping. Rotordynamic fluid force and moment with frequency dependence which are generated in impellers and runners of turbomachinery, shaft seals and fluid bearings have a large effect on rotor vibrations. Especially a tangential fluid force and a normal fluid moment which foster a destabilizing action lead to self-excited vibrations.
It is generally considered that the characteristics of the rotor vibration mainly depend on the stiffness and damping of bearings which support a rotating shaft. In order to meet the demands of the high efficiency and performance, operating clearances between rotating and stationary components become smaller year by year. Therefore, it is required to know how the fluid in the small clearance affects the rotor behavior.
The rotordynamic fluid force and moment, and related issues in turbomachines are dealt within this forum.

Non-exhaustive list of suggested Topics:

- Rotordynamic fluid force and moment, and rotordynamic coefficients:

- force and moment on the shroud of impeller and runner

- fluid forces in inducer

- torque unbalance forces in turbine

- dynamic characteristics of seals and bearings

- Nonlinear characteristics of fluid forces

- Damping and vibration control techniques

- CFD analysis and techniques

- Experimental approaches

- flow model and theoretical analysis

- Lateral and angular vibrations of rotor and their instability