双模式消声器气流再生噪声试验与仿真

为探究双模式消声器气流再生噪声,搭建了消声器试验台架,采用双传声器传递函数法和消声器静态传递损失法,在不同进口流速下,测量了双模式消声器在阀门关闭和打开状态下出口端气流再生噪声入射声功率和尾管噪声。试验结果表明,阀门打开时气流再生噪声与尾管噪声均降低,出口端气流再生噪声入射声功率最高下降1.1dB,尾管噪声最高下降2.3dB,直接验证了双模式消声器有助于降低气流再生噪声的特点。在试验基础上,建立了双模式消声器三维模型,通过Fluent有限元软件对消声器内部流场进行数值仿真,获得了消声器内部压力、气流流速及湍动能的分布特性。仿真结果表明,阀门打开时消声器内部压力、气流流速及湍动能均比阀门关闭时低。仿真和试验结果基本吻合。

Test and simulation of the flow regeneration noise of dual mode muffler

In order to explore the flow regeneration noise of the dual-mode muffler, a test bench was built. The flow regeneration noise and tailpipe noise were measured with the valve closed and opened respectively at different inlet flow rates by the methods of dual-microphone transfer function and the muffler static transmission loss. The test results show that the flow regeneration noise and the tailpipe noise are both reduced when the valve is opened, and the incident sound power of the flow regeneration noise at the outlet drops down to 1.1 dB, and the tailpipe noise down to 2.3 dB, which directly proves that the dual-mode muffler can help reduce the flow regeneration noise. Based on the test, a three-dimensional model of the muffler was built, and the flow field simulation inside the muffler was performed by Fluent, obtaining the distribution characteristics of pressure, airflow velocity and turbulent kinetic energy. The simulation results indicate that pressure, airflow velocity and turbulent kinetic energy of the muffler are reduced when the valve is opened. The simulation and experimental results are basically in agreement.