擋板配置對圓形截面消音器性能影響之實驗 研究

Experimental Study on The Performance of Circular Mufflers with Different Placement of Baffles

楊詩韻(Shih-Yun Yang)

指導教授 ： 張英俊

大同大學/工程學院/機械工程學系所/碩士(2009年)

摘要

本文主要探討垂直擋板和消音材料於圓型消音器內的配置，進行量測分析，了解較佳的消音器內部配置。其中在可變參數裡，有變化的材料有，垂直擋板的間隙、消音材料的數目及擋板與消音材擺放方式，接著做消音性能實驗，分析實驗數據，製成聲音穿透損失頻譜圖及八音度頻譜圖，讓我們清楚知道其不同配置時，消音性能的好壞。
實驗初步以消音材料片數與前擋板間距離作為變動參數，發現消音器的擋板間距越窄與消音棉片數增加時，消音性能有大大的提升，還有擋板與消音材料兩者相互平行或垂直的擺放，讓噪音源進入消音管後，因反射路徑的不同，可大幅降低噪音；從穿透損失頻譜圖明顯地看出來與沒加裝擋板時的差異，在1000Hz時噪音降低量提升到55dB；加入消音棉後一片與二片的性能差異變化較小，但相對於在三片吸音棉時，3000~5000Hz高頻降噪量有明顯穩定的成長，加入擋板與消音材料後低頻之消音性能也有相對的提升。
除此之外，消音材料性質不同對於消音器之影響於800Hz後開始明顯提升，對高頻之影響效果也是十分顯著。

關鍵字

消音器 ； 聲音穿透損失 ； 消音性能 ； 擋板 ； 消音材料

並列摘要

This article mainly probes into the configuration of the vertical baffle and the sound muffling material in a circular muffler, doing measurement analysis in order to know a better configuration within a muffler. Among the variable parameter, the material with variation includes: the interval between the vertical baffles, the number of sound muffling material, and the layout of the baffle and the sound muffling material. The following is the experiment of the noise-damping capability, analyzing the experiment data, and making the sound-penetrating-loss spectrum and the octave spectrum to let us know clearly that when the layout is different, the noise-damping capability is different.

The initial experiment is to use the number of sound muffling material and the interval of the front baffle as the variable parameter. It is found that when the interval of the baffles is narrowing and the number of the sound muffling cotton pad is increasing, the noise-damping capability is raising conspicuously. Also, when the baffle and the sound muffling material are horizontal or vertical to each other, it could considerably decrease the noise when the source of the noise enters the hush pipe because the reflecting paths are different. It’s clear that according to the sound-penetrating-loss spectrum, the differences can be seen clearly when it’s without baffles. When the frequency is at 1000Hz, the amount of the noise could reduce to 55dB. The capability difference is smaller after adding one or two sound muffling pads, but when it is comparing with three sound muffling pads, the reduction of the amount of noise when at high frequency, 3000~5000Hz, is growing obviously and steadily, and noise-damping capability at low frequency is comparatively increasing when adding the baffle and the sound muffling material.
Apart from that, the influence of the different sound muffling material characters to the muffler starts to increase clearly after 800Hz, and the effect to high frequency is also obvious.

並列關鍵字

muffler ； sound-penetrating-loss ； noise-damping c

參考文獻

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