Research on the influence of annular flow on critical speed of integrated motor pump rotor system

The integrated motor pump, as the core unit of the electro static hydraulic actuator, directly determines the dynamic performance of the actuator. The background of aerospace applications demands high reliability, high power density, and strong environmental adaptability for elector-hydraulic actuators. However, in complex working conditions of high voltage and high speed, the characteristics of the integrated motor pump rotor system are easily affected by the surrounding annular flow, leading to instability and failure. To solve the problems above, an accurate mathematical model for annular flow is established. Based on the ANSYS Workbench simulation platform, the characteristics of the internal annular flow field of the actuator under different fluid viscosity, rotor speed, and circulation gap are analysed. The mechanism and influence of annular flow on the critical speed of the integrated motor pump wet rotor system are studied, and the resulting method provides theoretical support for the design of high-performance integrate motor pump.