Research On Flow Field Measurement And Structural Parameter Matching For The Pilot Stage Of Jet Pipe Servo Valve

Compared with the double nozzle flap servo valve,the jet pipe servo valve is highly resistant to pollution and has high reliability.It is widely used in aviation,aerospace,ship and other fields.Due to the complicated internal flow for the pre-stage of jet pipe servo valve,there are submerged jets,wall flow and impinging jets;it is difficult to accurately analyze and calculate theoretically,which makes it difficult to accurately predict the performance of the jet pipe servo valve.The static characteristics of the pre-stage are mainly obtained by a large number of experiments,which greatly increases the research cost and the development cycle.Therefore,this paper uses the combination of numerical simulation and particle imaging velocity measurement technology to study the flow field characteristics for the pre-stage of jet pipe servo valve.This research work is of great significance to the forward design and product optimization of the jet pipe servo valve.In this paper,the CSDY-type jet pipe servo valve is taken as the research object.Firstly,its structure and working principle are introduced.Then,the pre-stage test model of the jet tube servo valve is designed by using the Reynolds similarity theory.The particle image velocimetry technique is used to measure the flow field of the jet valve pre-stage in different jet deflection angles and different flow rates,and the flow characteristics and velocity distribution of the pre-stage flow field are obtained.The numerical simulation is used to simulate the flow field for the pre-stage of jet pipe servo valve.Considering the turbulence model,the number of grids and other factors,the numerical model for the pre-stage of jet pipe servo valve is established.The correctness of the model is verified by comparing the PIV test results.The influence of nozzle hole diameter,receiving hole diameter and nozzle-to-receiver distance on the flow field characteristics and recovery pressure of the main parameters of the pre-stage is analyzed.The matching scheme of the main parameters of the jet valve servo valve pre-stage is proposed.The numerical simulation method is used to calculate the nozzle hole diameter,the receiving hole diameter and the nozzle-to-receiver distance.The combined pre-stage recovery differential pressure and stability analysis obtained the optimal structural parameter matching range of the pre-stage under different flow of jet pipe servo valve.