Research On Fluid-structure Interaction Dynamics Characteristics Of Jet Tube Under Submerged State

Jet tube electro-hydraulic servo valve has many advantages such as high reliability,high anti-pollution ability,long life,etc.,so it is widely used in military,aerospace,construction machinery,shipbuilding and other industrial fields.However,because the internal flow field of the servo valve is more complicated,the jet tube in its internal chamber is often impacted and vibrated at high frequency,which leads to changes in its dynamic flow field characteristics,which in turn leads to a decrease in the pressure control accuracy of the jet tube valve,or even failure Wait for the situation.At the same time,due to the micro-scale of the jet tube and the servo valve chamber and the limitation of experiments and simulation methods,there are few researches on it.The fluid-structure interaction dynamics of the jet tube needs to be further revealed.Therefore,this subject will learn from the existing fluidstructure interaction dynamics theory,combined with PIV(Particle Image Velocimetry)transient flow field testing technology and ANSYS multiphysics co-simulation technology,to study the fluid-structure interaction dynamics characteristics of the jet tube in the submerged state.According to the pre-stage flow field model of the servo valve,the dynamic similarity principle is used to simplify and amplify it,and the model experiment platform is built,and then the dynamic flow field is measured by PIV technology.The effects of Reynolds number Re and jet tube end profile(wall constraint)on the generation of vortices in the gap are studied,and the experimental data are analyzed by vorticity analysis and intrinsic orthogonal decomposition(POD)analysis.The dynamic flow field characteristics of different jet tubes impinging jets at close range in the submerged state are obtained.Considering the fluid-structure interaction effect of the interaction between the jet tube and the flow field,the flow field of the pre-stage is simulated and analyzed,and the fluidstructure interaction vibration law of the slender jet tube under the impact of high-speed fluid in a confined space is obtained.At the same time,the fluid-solid interaction dynamics characteristics of three different jet tubes with different contours are compared,and a more reasonable structure of the jet tube is obtained.The structure optimization of the jet tube under flow-induced vibration conditions was carried out,and the tapered jet tube was introduced.The benchmark jet tube and the tapered jet tube are analyzed and compared under flow-induced vibration conditions to explore the dynamic characteristics of fluid-solid coupling.The results show that the tapered jet tube is more effective in maintaining the stability of the pressure difference and restraining the flow instability and the fluid-structure interaction vibration characteristics.It has laid a solid foundation and has important theoretical and practical significance.