基于仿真离散数据的偏转板射流式伺服阀液动力计算方法研究

Research on the Calculation Methods of Fluid Force at Prestage of Jet Deflector Servo Valve Based on the Simulated Discrete Data

基于偏转射流式伺服阀工作机理,提出关于其动态特性分析及前置级液动力计算检测的问题。建立关于力矩马达、射流盘前置级以及功率滑阀三部分的完整伺服阀动态模型,确定前置级液动力的近似公式,并对整阀特性进行频率分析,验证了数学模型的正确性;建立伺服阀前置级内部的二维流场模型,并基于流场仿真所获得的离散数据,给出两种可用于计算稳态液动力的方法,即动量定理法和压差法,通过计算某型伺服阀的液动力,验证上述两种方法能够相互印证;设计并实现了一种双自由度的液动力测试平台,实现了对液动力的间接测试。结果表明,采用动量定理法和压差法计算得到的液动力值,与其近似计算公式以及试验结果一致,证明了提出的液动力计算方法与测试系统均具有可行性,为此类伺服阀的改进与优化提供了技术支撑。

The problem of the dynamic characteristics analysis and prestage fluid force calculation of the jet deflector servo valve is investigated based on its operation mechanism. A dynamic model including a torque motor, a prestage jet plate and a spool valve is established. An approximate formula of fluid force is obtained and the frequency characteristic of the whole valve is analyzed. A two-dimensional model about internal flow field of the jet deflector prestage is built. Furthermore, the momentum principle method and the differential pressure method based on the simulated discrete data are designed to obtain the steady-state fluid force. These two methods are applied to fluid force calculation of a servo valve’s prestage and can confirm mutually. A two-degree of freedom test platform for measuring prestage fluid force indirectly is designed. And the experimental results about fluid force are consistent with the calculation according to the simulated data and the calculation from the theoretical formula, which proves the feasibility of the calculation and measurement method of prestage fluid force.