射流管伺服阀前置级建模及参数匹配研究

为研究射流管伺服阀前置级结构参数对前置级性能的影响，建立了伺服阀前置级数值模型，并利用PIV技术对前置级流场测量，验证了数值模拟模型的正确性.运用数值手段，分析了前置级主要参数喷嘴孔直径、接收孔直径及喷嘴至接收器距离对恢复压差及其稳定性的影响，获得了三种不同伺服阀流量下前置级最佳结构参数匹配范围.结果表明:喷嘴孔直径为0.22～0.28 mm时，接收孔直径与喷嘴孔直径之比的最佳取值区间为1.1～1.2，喷嘴至接收器距离与喷嘴孔直径之比的最佳取值区间为0.6～0.8.前置级结构参数对接收孔压差稳定性具有直接影响，参数不匹配导致接收器劈尖对不稳定射流边界层的剪切是造成接收孔压差振荡的重要原因. 

Modeling and Parameter Matching for the Pilot Stage of Jet Pipe Servo Valve

In order to study the influence of the structural parameters of the jet pipe servo valve on the performance of the pilot stage, a pilot stage numerical model of the servo valve was established, and the numerical simulation results of the pilot stage flow field was verified by using the PIV technology. The effects of nozzle hole diameter, receiving hole diameter and distance between nozzle and receiver on the restoring pressure difference and its stability were analyzed by means of numerical method. The optimum matching range of structural parameters of the pilot stage under three different flow rates of servo valves was obtained. The results show that, when the diameter of the nozzle is 0.22~0.28 mm, the optimum range of the diameter ratio of the receiving hole to the nozzle hole diameter is 1.1~1.2, and the optimum range of the ratio of the distance between nozzle and receiver to the nozzle hole diameter is 0.6~0.8. The pilot stage structure parameters have a direct influence on the stability of the differential pressure of the receiving hole. The unstable of jet boundary layer by receiver wedge due to parameter mismatch is an important reason for differential pressure oscillation in receiving hole.