Research On Magnetic Field And Flow Field Characteristic And Experiment Of Giant Magnetostrictive Materials-based Electro-hydrostatic Actuator

With the concept of "More-Electric Aircraft" and "All-Electric Aircraft" is put forward that the advantage of power-by-wire actuating system has been more and more obvious. Electro-hydrostatic actuator with small size and high-frequency bandwidth is imperative for power-by-wire time, which can be achieved by application of smart materials and structures. For this purpose, GMEHA(Giant Magnetostrictive materials-based Electro-Hydrostatic Actuator) is developed with giant magnetostrictive materials as the driving core in this paper, and research on magnetic field and flow field characteristic and experiment of GMEHA are carried out.First of all, the structure of GMEHA has been designed according to the application characteristic of giant magnetostrictive materials and working principle of electro-hydrostatic actuator. The design philosophy and functional characteristics of main parts have been introduced detailedly and systematically. The solutions have been put forward in allusion to the key technology in design of GMEHA. Secondly, the characteristics of magnetic field and flow field are analyzed respectively. The driving magnetic field is provided by combination of permanent magnet and controlling coils. The mathematic model of magnetic circuit is also set up and the mapping rules between the main structure parameter of magnetic circuit and the distribution uniformity of magnetic circuit by the method of combination of finite element analysis and experiments. Based on mechanics principle of fluid-structure-interaction, the fluid models of cantilever reed valves, pump chamber and tube within GMEHA are set up in COMSOL Multiphysics software. The response characteristics of reed valve under constant pressure and sinusoidal pressure difference and the deformation of reed valves and the pressure loss in tube under constant pressure difference are studied. Thirdly, the theoretical model of GMEHA is set up and analyzed. The output displacement sensing model of giant magnetostrictive actuator is set up based on Jiles-Atherton hysteresis model and the dynamic applicability of model is improved by considering the influence of power supply and eddy current. Dynamic mathematic model of machinery-fluid module is set up according to fluid-structure-interaction characteristic of reed valves and dynamic characteristic of pump chamber and tube. The dynamic simulation model of GMEHA is set up by MATLAB/Simulink, in allusion to which the system simulation research is studied, the theoretical mapping relation between the output flow rate, driving current, working frequency and other relevant parameters of GMEHA and the influence on the dynamic output performance of GMEHA by each part are achieved. Finally, the experimental prototype of GMEHA is manufactured and the experimental test platform is set up, output characteristics of GMEHA is on experimental study and the experiment results show that the GMEHA achieves the maximum no-load flow rate of 1.3L ? min-1 with the optimum working frequency of 225 Hz, the load capacity can reach more than 14 kg and maximum output power approach 3.21 W.