SQUEEZE FILM DAMPER DYNAMIC STIFFNESS ANALYSIS, TAKING INTO ACCOUNT THE END GAP

One of the most common ways to reduce vibration in engines is the use of damping devices in the rotor supports. Damping devices may affect both the amplitude of the oscillations and the critical frequencies. The most commonly used damping devices are the squeeze film dampers (SFD), which can show dynamic stiffness that is proportional to frequency of oscillations and that is depends on the relative amplitude of oscillations. The stiffness of the damper is highly influenced by the end gap, which is also often seen as a non-contact radial clearance seal. In this work, a method is proposed that will take into account the effect of end gaps on the dynamic stiffness of a SFD. As a result of the calculations, it was found that the size of the end slots significantly affects the dynamic stiffness of a short SFD, and in some work modes it can exceed the stiffness of supports and bearings.