减压阀动态特性的数值模拟及故障分析

采用ANSYS有限元软件计算得到减压阀膜片的反力时程曲线和运动部件的动态特性，在此基础上将结构简化为两个单自由度质量弹簧阻尼动力学模型，采用Newmark算法计算。流体控制方程为三维非定常积分形式的ALE(Arbitrary Lagrangian Eulerian)方程，采用基于弹簧近似的动网格有限体积格式求解，应用了新的离散几何守恒律和高精度界面算法；同时采用虚拟网格通气技术实现阀门部件运动过程所引起的拓扑变化。计算表明，在较宽的上游增压速率范围内减压阀出口压力存在振荡，均值接近按照静态性能设计的理论值。通过对计算流场进行分析，确定了造成两种开启故障的主要机理，修改模型参数可以排除异常。

Numerical simulation of dynamic properties of pressure relief valve and fault diagnosis

Using ANSYS to calculate the force response curves with time history of pressure relief valve and dynamic characteristics; Solid structure was simplified to two single degree of freedom mass spring damper dynamic models which could be calculated by Newmark algorithm. The three-dimensional unsteady integral forms of ALE equation were solved by finite volume scheme based on spring analogy method and dynamic grid. A new discrete geometric conservation law and high-precision fluid and solid coupling algorithm were used to calculate the governing equations; the virtual mesh ventilation method was adopted to resolve the problem when multi bodies moved from contact to separation and the mesh topology changed. The results show that the outlet pressure of valve oscillated within wide range upstream pressurization rate, the average pressure is close to the theoretical value of static performance design. Through the flow field analysis, it can determine the main mechanism of two kinds of open fault and modify the model parameters to exclude anomalies.