The swash plate piston pump is widely used in the hydraulic system of helicopter fatigue test, because its flow characteristics are critical to the stability of the hydraulic system. This paper used the three-dimensional geometric method to analyze the movement track of the plunger in the swash plate piston pump, and derived the formula of the overflow area based on the graphic analysis method. The corresponding Matlab program was compiled to realize the automatic calculation of the overflow area of oil suction and drainage stage. It constructed a single piston flow model considering flow reversal and leakage, combining AMESim software realized the transformation of the three-dimensional calculation model of the piston pump to a one-dimensional calculation model. Based on the calculation results of the initial operating conditions, this paper analyzed the flow characteristics of the piston pump and the reasons for its flow pulsation. The accuracy of the one-dimensional computational model was verified by the flow pulsation calculation results of the three-dimensional model based on the Computational Fluid Dynamics (CFD) method. On this basis, it analyzed the influence of different operating conditions (including operating temperature, working pressure and piston pump regulating parameters) on the outlet flow pulsation rate. And it analyzed the key points of adjusting and controlling the piston pump in helicopter fatigue test from the angle of reducing the flow pulsation rate and improving the test accuracy. The one-dimensional calculation model proposed in the paper can significantly improve the simulation calculation speed of piston pump, facilitate the improved design of the subsequent piston pump and be added to the virtual digital test platform as a subsystem. © 2024 South China University of Technology. All rights reserved.
