Rotor Active “Anti-Swirl” Control

Rotor self-excited vibrations due to solid/fluid interaction, such as occurring in seals, can easily be reduced or eliminated by controlling fluid circumferential velocity. This is known as “anti-swirl” technique. An active “anti-swirl” control system for rotating machines is described in the paper. While mainly controlling rotor self-excited vibrations, this active control system reduces also rotor lateral vibrations caused by other factors (such as unbalance), by increasing the system effective damping.