关键词: 轴向柱塞泵, 多相流耦合, 流量特性, 配流盘, 空化抑制

Abstract: The high-pressure axial piston pump is the power source in the hydraulic system of aircraft control surfaces. To break the monopoly of the key technology for high-pressure piston pumps in the list of the United States, and aim-ing to satisfy the requirement for precise rudder control in the large civil aircraft C919 during navigation, this study conducted numerical simulations and optimization of internal flow characteristics in the pumps based on full cavita-tion models and compressible models. The numerical simulations were validated by a series of experiments. The reasons for the formation of flow valleys and peaks are revealed by analyzing the flow characteristics, the way cavi-tation impacts flow pulsation is discovered, and a method to suppress cavitation in the piston chamber is proposed. Conclusions : Backflow is the main cause of the drainage flow valley. Drainage flow peak (i.e., pressure overshoot) is caused by two reasons: The inertial impact of backflow hydraulic oil causes a sudden increase in cavity pressure, Hold pressure due to untimely and incomplete overflow after the end of the backflow makes the pressure over-shoot; Reveal that gas bubbles in the piston chamber absorb the "intended boost" and prolong the back-up time, thus reducing the flow valley; The mathematical model for suppressing the cavitation of the piston chamber under the invariable theoretical flow rate is established by innovatively coupling the piston chamber flow rate equation and the pressure drop equation from the perspective of pressure drop in order to solve the problem that suppress-ing the cavitation of the piston chamber reduces the theoretical flow rate. Based on the model, two methods are proposed to suppress the cavitation of the piston chamber without changing the theoretical flow rate, and this study can provide theoretical solutions for the development of military axial piston pumps.

Key words: axial piston pumps, multiphase flow coupling, flowrate characteristics, valve plates, cavitation suppression