消声器测量回路系统的噪声预测

The noise prediction of the measurement loop system of silencer

气动技术的发展大大推动了工业自动化和生产现代化的进程，但气动回路系统的气流噪声是气动技术的主要缺点，气动降噪引起了工业应用部门和学术界的广泛关注。木文以消声器测量回路系统为例，对回路系统的噪声源进行了分析。首先用三维ＬＤＶ系统对系统中用于电磁阀等排气噪声的声源的孔板的流场进行了测量，较为翔实的得到了平均速度及湍流强度和雷诺应力等湍流量，分析了其同一般的收缩喷嘴射流的异同关系。同时测定其声场，分析其噪声方向特性，找出了声场和流场的一些内在关系，揭示了孔板的噪声产生机理。并对孔板这一声源进行了分析，提出了精确的孔板噪声预测公式。最后对回路系统的其他部分的噪声进行了预测，综合预测结果同实验吻合较好，为气动系统的降噪提供了理论指导。

Pneumatic technology has come to a prosperity in recent years, which leads to a further automatization of the whole industry. However, in industrial pneumatic applications, pneumatic noise has shown its serious ponderance. The research of the attenuation of pneumatic noise has been more and more concerned, which has important academic value along with great economic benefit. At first, The characteristics of flow field such as mean velocity and turbulent intensity etc. of orifice are accurately acquired by 3D-LDV system. Orifice is the simulative noise source of solenoid valve in pneumatic loop system. The difference between the jet flow and orifice flow is analyzed. At the same time, the sound field and noise radiate directions are measured, some internal relationships and noise mechanism between flow and sound held of orifice are found. At last, The noise source in the measurement loop system of silencer is analyzed, which is an example of pneumatic loop system. As same as the prediction formula of radiated noise in the loop system is presented, which is well coincident with experiment result. These results provide the theory guidance for the noise attenuation in pneumatic loop system.