Insight into the effect of air ingestion on the film characteristics of a special squeeze film damper

The research of unclear influence of air ingestion on the characteristics of squeeze film damper (SFD) oil film was carried out. The fluid domain was modeled. Influences of air ingestion were analyzed under different structure and working conditions. Mechanism of air ingestion on the characteristics of oil film was revealed. Results uncover that air ingestion occurs at the outlet boundary and have a significant inhibition on the cavitation effect. It is affected by whirl radius, clearance ratio, width, and oil supply pressure. Air ingestion has significant effects on maximum pressure, oil film force, moment at time T, oil film force in the x direction, oil film force in the y direction, oil film resultant force, and minimum pressure fraction. Moreover, the stability of damping and stiffness is improved due to air ingestion. Increasing aspect ratio, oil supply pressure, and reducing whirl frequency can improve dynamic characteristics. The results provide theoretical basis for the optimized design of SFD.