Experimental and theoretical results of the performance of controllable clearance squeeze film damper on reducing the critical amplitude

Aiming at the non-optimal performance of SFD under different operating conditions, this paper proposes a controllable clearance squeeze film damper (CCSFD) that uses hydraulic pressure to adjust the radial clearance and establishes a corresponding test rig. Measure the critical amplitude under different imbalances and hydraulic pressures. Give the calculation formula of hydrodynamic force by directly integrating pressure distribution and build the corresponding numerical model. Both experimental and numerical results show that CCSFD can achieve synchronous adjustment of the damper's performance under a non-stop state of the rotor system. In this case, the radial clearance can transform actively in the range of 1.75-3.19 parts per thousand, which carries out a noticeable improvement of the damper's performance and achieves satisfactory performance under different operating conditions.