安溢活门动态流场数值模拟研究

Numerical Simulation Research of Safety Valve Dynamic Flow Field

为了研究安溢活门主阀开启过程中的动态流场特性,采用Fluent动网格法和用户自定义函数方法对其进行流固耦合数值模拟。通过Fluent 3D非定常显式耦合求解器以及虚拟挡板技术求解某时刻主阀腔内的气压力,并通过有限气容充放气过程方程确定背压腔充放气过程对膜片的气压力,得到膜片上的总和力。进而通过求解质量弹簧阻尼系统动力学方程确定主、副活阀的运动速度和位移。结果表明:活门开启过程中开度越大,阀道内流场越复杂,流动越不稳定;活门开度增大,阀座处流量线性增加,入口腔流量变化平稳,而出口腔流量波动较大;随着开度增加,活门不同位置和膜片上的气压力变化规律不同。

To research the dynamic flow field characteristics of main valve during the safety valve opening peri- od, the Fluent dynamic mesh method and user-defined function method are used for fluid-structure interaction numerical simulation. The pressure load of main valve is obtained through Fluent 3D unsteady explicit coupling solver with virtual baffle technique, and the pressure load of diaphragm during filling and exhausting process is obtained by solving the air-capacitor filling and exhausting process equation. And then the valve speed and dis- placement are solved through the mass-spring-damping system dynamic equation with total force of diaphragm. Results show that flow field becomes more complex and unstable with larger valve opening degree. With open ing degree increasing, throat flow mass increase linearly, inlet flow changes smoothly and outlet flow has an un- smooth fluctuation. Also, the pressure loads located on diaphragm and different places of valve vary differently.