During the takeoff phase of an aircraft, the aviation lubrication system exhibits a significant increase in lubricating oil temperature, which consequently affects the output characteristics and stability of the lubricating oil pump. This study focuses on a specific type of aviation lubricating oil gear pump. A test platform capable of simulating lubricating oil temperature rise within the range of 10–95 °C was established. By varying the rotational speed and outlet pressure, the influence of temperature rise on flow characteristics was investigated. The results indicate that under constant rotational speed, lubricating oil temperature rise leads to reduced flow rate, decreased volumetric efficiency, increased flow pulsation rate, and reduced torque, with the degradation rates of flow rate and volumetric efficiency accelerating when the temperature exceeds 60 °C, while at an outlet pressure of 2.2 MPa, the flow pulsation rate and torque are minimally affected by the temperature rise; under constant outlet pressure, lubricating oil temperature rise significantly impacts volumetric efficiency, flow pulsation rate, and torque, with greater effects at lower rotational speeds, and when the temperature exceeds 60 °C, the volumetric efficiency degradation rate increases while the flow pulsation rate growth slows and torque variations stabilize, with the flow pulsation rate being minimized and the torque being least affected at a rotational speed of 1000 rpm; additionally, lubricating oil temperature rise can partially mitigate speed loss phenomena, and the critical operating condition inflection points where the lubricating oil temperature rise impacts the pump performance are identified as approximately 60 °C, 2.2 MPa, and 1000 rpm.
Zhang et al. (Sun,) studied this question.