Active Vibration Control of Rotating Machinery With a Hybrid Piezohydraulic Actuator System

An integrated, compact piezohydraulic actuator system for active vibration control was designed and developed with a primary application for gas turbine aircraft engines. Copper tube was chosen as the transmission line material for ease of assembly. Liquid plastic, which meets incompressibility and low-viscosity requirements, was adjusted to provide optimal actuator performance. Variants of the liquid plastic have been prepared with desired properties between −40°F and 400°F. The effectiveness of this hybrid actuator for active vibration control (AVC) was demonstrated for suppressing critical speed vibration through two critical speeds for various levels of intentionally placed imbalance. A high-accuracy closed-loop simulation, which combines both finite element and state space methods, was applied for the closed-loop unbalance response simulation with/without AVC. Good correlation between the simulation and test results was achieved.