Thermal-hydraulic Modeling and Simulation of the Hydraulic System based on the Electro-hydrostatic Actuator

Abstract

Electro-hydrostatic actuator (EHA) was a typical power-by-wire (PBW) actuator, which was widely-used in large commercial aircrafts, such as Airbus A380. The electro-hydrostatic actuator(EHA) had the advantages of small sizes, light weight, high power density, high reliability and maintainability. With the application of EHA in large commercial airplanes, the airworthiness certification of EHA became an new problem. The precondition of the airworthiness certification of EHA was to understand its operating principle and characteristic. Because of no centralized hydraulic oil tank and short cycle oil circuit, the temperature-rise of the hydraulic system in EHA always kept high during operation. Therefore, it was important to build the thermal-hydraulic models of the hydraulic system in EHA, and to do the thermal analysis of the EHA by this model. In this paper, a lumped-parameter thermal-hydraulic model of the hydraulic part in EHA was proposed. The model was built based on the detailed analysis of the heat transfer of the hydraulic part in EHA. By the simulation of a practical system and the comparison with the traditional hydraulic system, the accuracy and practicality of this model was verified.