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为了考虑结构变形对关机水击特性的影响,应用Workbench15.0构建双向流固耦合分析系统,模拟关机水击过程,通过压力和流线的分布图分析压力波传播和能量耗散。根据轨控发动机大流量、高室压、快响应的发展趋势,设计了8个工况来分析流量、压力、阀门关闭时间对水击特性的影响。仿真结果表明:在水击发生后,水击的能量只有小部分通过从入口流出和结构变形而耗散,大部分水击能量的耗散是由于流体的粘性损失。流量只对水击峰值压力有影响,且流量越大,水击峰值压力越大。阀门关闭时间的缩短增加了峰值压力和水击频率,减缓了衰减速率。管路背压对水击特性几乎没有影响。因此,在进行轨控发动机高室压水击试验时,在保证流量和关阀时间相同的情况下,减小出口背压,可以得出与高背压一致的水击压力变化曲线。

In order to consider the effect of structural deformation on water hammer characteristics, two-way FSI analysis system was built to simulate water hammer.The propagation of pressure wave and energy dissipation were analyzed through pressure and streamline distribution.According to the development trend of orbit-control engine, eight working conditions were designed to analyze the effect of backpressure, flux and valve closing time on water hammer characteristics.The simulation results indicate that, only a small part of the energy of water hammer is dissipated through flowing out from the inlet and the structural deformation, and most of the energy dissipation is due to the viscous loss of the fluid.The flux only affects the peak pressure of water hammer.The greater the flux is, the larger the peak pressure of water hammer is.The shortening of valve closing time increases peak pressure and frequency of oscillation, and reduces the attenuation rate.Backpressure has no effect on water hammer characteristics.Therefore, in the high-pressure water hammer test of orbit-controlled engine, the outlet back-pressure can be reduced under the same flux and valve closing time, and the water hammer pressure curve consistent with that under high backpressure can be obtained.

引言
1 物理模型和计算方法
2 算例验证
3 水击特性
4 结论

图1 模型及球阀结构<br/>Fig.1 Model and structure of ball valve

图1 模型及球阀结构
Fig.1 Model and structure of ball valve

图2 管横截面网格
Fig.2 Mesh of profile of pipe

图3 流固耦合仿真平台<br/>Fig.3 The simulation platform of FSI

图3 流固耦合仿真平台
Fig.3 The simulation platform of FSI

表1 仿真值与试验值误差<br/>Tab.1 The error of simulation and experiment

表1 仿真值与试验值误差
Tab.1 The error of simulation and experiment

图4 仿真与试验水击压强变化曲线<br/>Fig.4 Water hammer pressure of simulation and experiment

图4 仿真与试验水击压强变化曲线
Fig.4 Water hammer pressure of simulation and experiment

表2 不同工况工作条件<br/>Tab.2 Working conditions

表2 不同工况工作条件
Tab.2 Working conditions

图5 不同时刻压力和流线分布图<br/>Fig.5 Pressure and streamline at different time

图5 不同时刻压力和流线分布图
Fig.5 Pressure and streamline at different time

图6 0.05 s时入口速度分布图<br/>Fig.6 Velocity distribution of inlet at 0.05 s

图6 0.05 s时入口速度分布图
Fig.6 Velocity distribution of inlet at 0.05 s

图7 不同时刻入口速度分布图<br/>Fig.7 Velocity distribution of inlet at different time

图7 不同时刻入口速度分布图
Fig.7 Velocity distribution of inlet at different time

图8 CFD和FSI计算方法水击压强变化曲线<br/>Fig.8 Water hammer pressure at CFD and FSI

图8 CFD和FSI计算方法水击压强变化曲线
Fig.8 Water hammer pressure at CFD and FSI

图9 不同流量下水击压强变化曲线<br/>Fig.9 Water hammer pressure at different mass flow rate

图9 不同流量下水击压强变化曲线
Fig.9 Water hammer pressure at different mass flow rate

图10 峰值压力与流量关系图<br/>Fig.10 Relationship between pressure and mass flow rate

图10 峰值压力与流量关系图
Fig.10 Relationship between pressure and mass flow rate

图11 不同关阀时间下水击压强变化曲线<br/>Fig.11 Water hammer pressure at different valve closure time

图11 不同关阀时间下水击压强变化曲线
Fig.11 Water hammer pressure at different valve closure time

图12 峰值压力与关阀时间关系图<br/>Fig.12 Relationship between pressure and valve closure time

图12 峰值压力与关阀时间关系图
Fig.12 Relationship between pressure and valve closure time

图13 不同背压下水击压强变化曲线<br/>Fig.13 Water hammer pressure at different backpressure

图13 不同背压下水击压强变化曲线
Fig.13 Water hammer pressure at different backpressure

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备注

引言

1 物理模型和计算方法

2 算例验证

3 水击特性

4 结论

期刊信息