基于Lighthill方程的球阀气体内漏喷流声场数值模拟

Numerical Simulation of the Jet Sound Field of Ball Valve Inner Leakage Based on the Lighthill Equation

建立考虑喷流扰动速度影响的Lighthill气动力声学方程。采用二阶加权平均中心差分隐格式方法,对不同内漏间隙下球阀气体内漏喷流声场进行了数值模拟。数值模拟结果表明,球阀内漏喷流流动伴随喷流噪声的产生。对于球阀结构,在发生内漏时存在二次截流,二次截流点为喷流噪声强度最高的位置。球阀通孔与阀体通道形成的过流空间是喷流噪声最强的区域。球阀下游流道喷流噪声强度要高于上游。模拟结果为球阀内漏声学检测提供了依据。

Based on the Lighthill aerodynamic acoustics equation and taking into account the influence of jet disturbance, the applicable formula is established. By using 2-weighted average central-difference hidden scheme, under the condition of different inner leakage clearances, the jet sound field generated by the inner leakage of ball valve is numerically simulated. Numerical result shows that the jet noise is always produced with the jet flow. For the structure of ball valve, second interception will come into being when inner leakage occurs, and the peak amplitude of jet noise is at the second interception point. The maximum intensity area of jet noise is the flow space formed by the through-holl of ball valve and channel of valve casing. The acoustic intensity of downstream is bigger than upstream. Numerical result provides theory basis for the acoustic detection of ball valve inner leakage.