射流管伺服阀前置级的动态流场分析

射流管电液伺服阀的喷嘴到接收孔间的流场较为复杂,尤其在射流管偏转及阀芯运动的动态情况下,会存在回流、漩涡等现象。以某型射流管电液伺服阀结构为模型,结合射流管偏转时的阀芯力平衡关系,得到阀芯的运动方程,应用雷诺平均方程和标准两方程模式的封闭方程,通过流体动力学软件FLUENT建立射流管伺服阀喷嘴到阀芯两腔的三维可视化模型,仿真分析了喷嘴到接收孔的前置级瞬态流场及阶跃响应。仿真结果表明:接收孔中的涡量强度会影响射流管电液伺服阀的阶跃响应,涡量强度越大、振荡越大、阶跃响应越慢,并通过试验测试阀芯位移验证了数值计算的正确性,同时对比了不同接收孔间夹角的同时刻涡量及阶跃响应,得到接收孔间夹角为45°的最优设计。研究方法和结果对于提高射流管电液伺服阀的动态响应有重要参考价值。

Dynamic flow field analysis of the prestage of jet pipe servo valve

The flow filed in the jet pipe and receivers is very complicated, especially in the dynamic situation, back flow and vortex etc. exist . Based on the model of a certain jet pipe servo valve, the movement equation of valve is obtained by combining force equilibrium of spool. Applying Reynolds averaged Navier Stokes equations and the standard two equation model (liquid phase), a visual simulation model of the jet pipe to receivers of jet pipe servo valve is established through fluid dynamic software FLUENT. The fluid field and transient response of the prestage are simulated and analyzed which is from jet pipe to receivers. Simulation results demonstrate that the intensity of vorticity has effects on step response of jet pipe sevo valve. The greater vorticity intensity results in the greater oscillation and the slower step response. The 45 degree is the best design of the angle between two receivers by comparing different angles between two receivers. This work has important reference value for improving dynamic response of jet pipe servo valve.