【作者】 王兵；

【导师】 戴光；

【作者基本信息】 大庆石油学院 ， 化工过程机械， 2007， 硕士

【摘要】 本文以承压阀门气体内漏这一工程问题为背景,研究针阀,球阀和闸阀的声学检测与评价。阀门内部流动状态比较复杂,气体喷流流场与声场相互作用,相互影响,从理论上很难准确分析气体喷流声场的特性。本文采用数值模拟和实验研究相结合的方法,通过对阀门气体内漏声场进行模拟,分析阀门气体内漏发声机理及声场特性,模拟分析结果对阀门气体内漏声学检测技术提供理论依据。阀门气体内漏过程产生的高速射流喷注不仅辐射四极子噪声,而且不均匀的气流还对噪声的传播起扰动作用。所以分析阀门内漏的流动状态及喷射噪声源的位置,强度,扰动速度的分布等情况可为内漏噪声场的数值模拟提供基础。内漏流场的模拟采用雷诺平均N-S方程和k-ε湍流模型作为控制方程,在空间上采用有限体积方法(FVM)二阶迎风格式对控制方程进行离散,时间上采用四阶Runge-Kutta法进行积分,流速和压力偶合采用SIMPLEC算法。根据阀门气体内漏流场模拟结果,得到扰动速度的分布函数,为阀门气体内漏声场模拟奠定基础。阀门气体内漏喷流声场的数值模拟采用加载速度扰动的声波动方程为控制方程,运用无条件稳定,高精度的加权平均三层隐格式差分方法,边界上综合运用Clayton-Engquist-Majda无反射边界条件和Dirichlet全反射边界,采用MATLAB软件进行编程计算和结果可视化输出。完成了轴对称射流噪声场及三种阀门气体内漏声场的数值模拟,同时分析不同上游压力和内漏状态对阀门内漏声场的影响及其声场特性,得到上游压力及内漏状态对内漏发声的影响规律。建立阀门气体内漏声学检测模拟实验装置,采用声学检测仪测试不同类型阀门内漏过程的声信号,获得阀门气体内漏过程声强及内漏率的实验数据,验证数值模拟结果的正确性。更多还原

【Abstract】 This paper takes the engineering problem of pressured valve gas inner leakage as background. Acoustic detection and evaluation of pin valve,ball valve and gate valve are studied. Because the flow state of fluid in the valve is complicated, and it has interaction between gas jet flow filed and their sound filed, it is difficult to analyze characteristics of sound filed truly through the theory method.Using the method of numerical simulation combined with experiment, the sound filed of valve gas inner leakage is simulated, then the origin of leakage noise and the characteristics of sound filed are analyzed. At last, the simulation results give theory supporting to acoustic detection technique of inner leakage. High speed jet generated by inner leakage not only radiates quadrupole noise, but also sound transmission is disturbed as refraction by the non-uniformity gas flow. So it is basic for numerical simulation of sound field to analyze the flow state, the position and amplitude of jet’s noise source, and distribution of disturbance speed. Simulation of inner leakage flow field make the Reynold’s average N-S equation and k-εturbulence model as control equation, which is discretized by second order upwind of finite volume method. Fourth order Runge-Kutta scheme is used for time integration, and SIMPLEC method is used to compute flow velocity and pressure coupled. The function of velocity distribution is confirmed by simulation results of flow filed, that provides a foundation for simulation of valve gas inner leakage.The numerical simulation of noise field uses the acoustic wave equation with disturbing as control equation, and uses non-condition stability,high order weighted average method with three floors implict difference to separate the equation. Clayton-Engquist-Majda non-reflect and Dirichlet all-reflect have been applied on boundary condition, meanwhile, the results can be visible by programming and using picture display function of MATLABL. The sound generated by axisymmetric jet and the inner leakage sound field of three kinds of valve can be simulated. Considering the factor of different pressure and inner situation, inner leakage sound field and characteristics can be analyzed at the same time, and rule of leakage noise is found.By establishing acoustic test device simulating the valve inner leakage, the signal generated by inner leakage of different valve can be collected, the experiment data of acoustic amplitude and inner leakage rate are gained, the numerical simulation results are proved accurate.更多还原