Research On Fluid-Structure Interaction Of A High-Frequency Electro-Hydraulic Flutter

With the development of industry, the need for flutter devices of large exciting force, high frequency, small amplitude and miniature size is becoming more and more urgent in projects. For the limit of frequency response characteristic of servo valve, it is difficult to increase the vibrating frequency of the traditional electro-hydraulic flutter, which is basically composed by cylinder or motor controlled by valve. So the research of increasing vibration frequency with large exciting force in hydraulic vibration technology has a very important significance.This paper elaborates the working principle of the electro-hydraulic flutter device with a cylinder controlled by a2D exciting valve, concentrates on the forced vibration of the elastic cover and the fluid-structure interaction of the exciting fluid, and analyses the vibration modal of the flutter device and its key component (the elastic cover). Build the vibration experimental platform for the study of the flutter device. The major work and achievements of this paper are as follows:1. Fluid-structure interaction analysis:using CFX and ANSYS to calculate the flow field and the structure field of the vibration chamber of the flutter for fluid-structure interaction united solution. Get the pressure waveform of the vibration chamber in different frequency with AMESim simulation and set the waveform as the inlet boundary condition for fluid-structure interaction analysis in CFX, which lead to the unsteady solution of the flow field and the transient dynamics analysis of the elastic cover.2. Modal analysis:obtain the natural frequency and vibration mode of the flutter device with the finite element modal analysis of the high frequency electro-hydraulic flutter device in ANSYS. Some improvement proposals are presented by the influence on the performance of the flutter device based on the vibration modal. The simulation result shows that the fluid lowers the each order frequency of the elastic cover with no effect to vibration modal, which is got from the fluid-structure interaction modal analysis of the key component of the flutter device (elastic cover).3. Experimental study of the flutter device:build the experimental platform. Study the change of the elastic stiffness of the elastic cover with the pressure, the influence on the vibration waveform by the change of the vibration chamber of the flutter device, and the effect to the resonant performance of the flutter device by different mass load. The flutter device vibrates very steadily in high frequency, which is proved by the experimental data.