| Author Name | Affiliation | | Renqi Zhang | School of Mechanical Science and Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China | | Congyun Zhu | School of Mechanical Science and Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China | | Guofang Ding | School of Mechanical Science and Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China | | Qibai Huang | School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China |
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| Abstract: |
| The exhaust flow velocity of the engine is an important parameter affecting the comprehensive performance of the muffler. The exhaust flow velocity increases by the regenerated noise generated in the muffler, which makes the sound absorption effect of the muffler worse. In order to solve this problem, a sound absorption method was proposed to reduce the flow rate of exhaust air by diverting and hedging the exhaust air, so as to improve the sound absorption. First of all, the airflow into the muffler was shunted by a conical shunt unit. Subsequently, the airflow entered the cavity of the perforated tube through the hole on the perforated tube. When the airflow was offset in the cavity of the perforated tube, it could reduce the flow rate of the exhaust airflow and improve the sound absorption effect. It could be concluded that the influence factors and the characteristics of the transmission loss were obtained by dividing the anechoic sub units of the whole structure, calculating the transfer matrix, and analyzing the function relationship between the independent variable and the dependent variable of the transmission loss, and the theoretical model was verified by experiments. The results of the experiment showed that the proposed sound absorption method can keep the transmission loss at a stable state under the condition of high-speed exhaust flow. For example, when the inlet air velocity increases from 15 m/s to 45 m/s, the maximum reduction of transmission loss is 6.5 dB in the range of 0-3000 Hz, which proves that the structure has a good effect of sound absorption. |
| Key words: regenerated noise split-stream-rushing rerforated tube transmission loss |
| DOI：10.11916/j.issn.1005-9113. 21038 |
| Clc Number:TB53 |
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| Descriptions in Chinese: |
| 分流对冲穿孔管吸声方法研究 张仁琪1，朱从云1，丁国芳1，黄其柏2 （1.中原工学院 机电学院，郑州 450007； 2.华中科技大学 机械科学与工程学院，武汉 430074） 摘要：消声器中排气气流速度是影响其整体性能的关键参数，随着发动机排气气流速度的逐渐增加，消声器内的再生噪声逐渐增加，导致消声器的吸声性能变差。为解决此问题，提出将排气气流进行分流与对冲来提高吸声性能的吸声方法。首先，通过使用锥形分流单元将气流进行分流，分流后的气流在穿孔管内腔发生对冲，从而降低气流流速提高吸声性能。通过对整体结构的消声子单元划分、传递矩阵的计算、传递损失自变量与因变量函数关系分析得到传递损失的影响因素与变化特性，并进行实验验证。实验结果表明：提出的分流对冲穿孔管吸声方法可在高速排气气流的情况下，始终维持稳定的传递损失，以入口气流流速从15m/s增加到45m/s为例，传递损失从26.5dB降低到24.5dB，降幅为0.075%，证明了提出的吸声方法具有良好且稳定的吸声效果。 关键词：再生噪声；分流与对冲；穿孔管；传递损失 |
