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采用流固耦合数值模拟研究了液体火箭发动机高压供气系统中的电磁阀在地面试验中出现的不稳定现象。固体结构采用质量弹簧阻尼单自由度模型描述,纽马克算法(The Newmark Method)求解;流体控制方程为三维Euler方程,采用基于弹簧近似动网格的ALE(Arbitrary Lagrangian-Eulerian)有限体积格式求解。程序应用了新的离散几何守恒律和流固界面算法,采用“虚拟挡板通气”技术实现电磁阀开启过程引起的计算区域拓扑变化。验证算例表明程序的有效性及算法的精度。数值模拟复现了试验中出现的故障,认为故障机理是典型的颤振现象,指出电磁阀和减压器之间的管路长度是影响气体激振力频率的主要因素。
The fluid-solid coupling numerical simulation was used to study the instability of the electromagnetic valve in liquid rocket motor high-pressure air supply system during the ground test. The solid structure is solved by the mass spring damping single-degree-of-freedom model described by The Newmark Method. The fluid control equation is a three-dimensional Euler equation and is solved by the ALE (Arbitrary Lagrangian-Eulerian) finite volume format based on a spring approximate mesh. The new discrete geometric conservation law and fluid-solid interface algorithm are applied to the program. The topological changes of the calculation area caused by the electromagnetic valve opening process are realized by using the “virtual damper ventilation” technology. Validation examples show the effectiveness of the program and the accuracy of the algorithm. Numerical simulations reproduce the faults that occurred during the test. The fault mechanism is a typical flutter phenomenon. It is pointed out that the length of the pipeline between the solenoid valve and the pressure reducer is the main factor that affects the frequency of gas exciting force.