Competition and synergy of vapor and gaseous cavitation in high-speed rotary vane pumps: Effects on performance and pressure pulsation

Rotary vane pumps are critical for lubrication delivery in aero-engines, yet their reliability is challenged by cavitation. Aviation lubricating oil inherently contains dissolved non-condensable gas, whose dynamic release and dissolution interact intricately with vapor cavitation, a phenomenon poorly captured in existing studies. This paper develops a unified numerical framework that integrates a dynamic dissolved gas transport model with the full cavitation model to simultaneously resolve vapor and gaseous cavitation in a high-speed rotary vane pump. The model is validated against experimental data, with a maximum relative error of 8.53%. Through systematic parametric analysis of suction pressure (101–20 kPa), oil temperature (25–120 °C), and rotational speed (4638–6910 r/min), the study elucidates the transient competition and synergy between the two cavitation modes. A critical regime transition is identified: gaseous cavitation dominates under standard inlet conditions, while vapor cavitation becomes increasingly prevalent below a suction pressure of 40 kPa or above an oil temperature of 50 °C. At elevated temperatures (120 °C) and low suction pressures (20 kPa), vapor volume fraction can exceed 30%, leading to severe performance degradation, including complete flow reversal. Furthermore, cavitation fundamentally modulates pressure pulsation characteristics, shifting the dominant excitation frequency from the two times of rotational frequency to the fundamental rotational frequency under high-speed, severe cavitation conditions. This work provides a foundational framework for designing cavitation-resistant pumps and defining safer operational limits for next-generation aero-engine lubrication systems, highlighting the necessity for tailored suppression strategies based on the dominant cavitation mode.