In order to explore the characteristics of dual mode mufflers, a resonance dual mode muffler was designed. The open angle of valve, pressure loss and sound tailpipe noise of the muffler were measured. The relationship of the entrance gas flow velocity, valve open angle, and pressure loss of the muffler was studied. The influence of valve switch conditions on the gas flow regeneration noise of the muffler was discussed. The test results show that the valve open angle increases nonlinearly with the flow velocity increase at the muffler inlet. The pressure loss and the gas flow regeneration noise of the muffler increase with the increasing of the gas flow velocity. But compared with the muffler without valve, the pressure loss and gas flow regeneration noise are both lower, and the decrement of the pressure loss increases with flow velocity increasing. Based on the test, a three dimensional mathematical model for the steady inner flow of the dual mode muffler was established, and the numerical simulation was carried out. The pressure and the velocity distributions of the inner flow were obtained. The simulation and the test results were basically in agreement.%为了探索双模式消声器的工作特性,设计共振腔式双模式消声器,测量不同入口气流流速条件下阀门的开度、消声器压力损失及出口声压.重点研究消声器入口流速、阀门开度、消声器压力损失之间的变化关系,讨论阀门打开和阀门关闭两种状态对消声器出口气流再生噪声的影响.试验结果表明:阀门开度随消声器入口气流流速的增大而增大,但成非线性;双模式消声器压力损失以及出口处的气流再生噪声都随着气流流速的增大而增大,但与无阀门设计的消声器相比,消声器压力损失和出口气流再生噪声均较低,并且压力损失降低的幅值随气流流速的增大而增大.在试验的基础上建立消声器内流流动三维稳态数学模型,并针对试验工况进行数值模拟,获得消声器内流场的压力、速度分布特性.仿真与试验结果基本吻合.
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