Simulation and experimental investigations on water-lubricated squeeze film damping stern bearing

In order to solve the contradiction between high load-carrying capacity and low natural frequency in designing ship water-lubricated stern bearing, an idea of independent design of load carrying and vibration reduction functions was proposed, and the squeeze film damper technology was innovatively introduced into a conventional water-lubricated stern bearing (CWSB) to form a water-lubricated damping stern bearing (WDSB). Harmonic responses of two bearings were calculated, and a dynamic characteristic experiment was carried out. The results show that the maximum displacement response (MDR) decreases with the increase in oil film clearance. With the increase in inner flange height, MDR increases first and then decreases. MDR decreases first and then increases with the increase in distribution angle. As rotation rate speeds, the difference between two bearings' Root Mean Square (RMS) vibration amplitude remains unchanged. As load increases, relative reductions of two bearings' maximum amplitude and RMS decrease. Amid a load of 0.2 MPa and a rotational speed of 200r/min, compared with CWSB, the maximum amplitude of WDSB in the vertical direction is reduced by about 71.8%, and the relative reduction in RMS is about 47.8%, which verifies the damping effect of WDSB is remarkable.

Automated summary

By introducing the squeeze film damper technology, the design of ship water-lubricated stern bearing successfully balances high load-carrying capacity and low natural frequency. Experimental results indicate that WDSB shows significant vibration reduction effect compared to CWSB.