关键词: 双喷嘴, 挡板, 电液伺服阀, 流场

Abstract:

The double nozzle flapper valve is the pre-stage of a two-stage electro-hydraulic servo valve, its structural parameters have an important influence on the performance of electro-hydraulic servo valves. This paper used the flow field computation software to compute the flow field of the nozzle's different structural parameter combinations, and also analyze the liquid flow property, as velocity characteristics, pressure characteristics, flow characteristics, etc. The results show that the flow rates increase as the the diameter, the end grinding and the external angle of the nozzle increase. But the differential pressure of the nozzle flapper valve decrease. And there is nearly no influence while changing the length of the nozzle, the inner angle of the nozzle and the cavity inner diameter of the nozzle. Through the comparisons and analyses the optimal combination of the structural parameters are found out,which can give the references  and provide a basis for the design of the nozzle of double nozzle flapper electro-hydraulic servo valves. 

Key words: double nozzle, flapper, electro-hydraulic servo valve;flow field