Acoustic quality factor and energy losses in cylindrical pipes
Acoustic quality factor and energy losses in cylindrical pipes
复制标题
圆柱形管道中的声学品质因数和能量损失
DOI：
10.1119/1.1308264
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发表时间：
2001
影响因子：
0.9
通讯作者：
D. L. Hatten
中科院分区：
文献类型：
--
作者：
Michael J. Moloney;D. L. Hatten
阻尼振荡器的品质因数 Q 等于 2π 乘以每个周期存储的能量与消耗的能量之比。这使得 Q 成为能量损失的敏感探针。使用适度的设备，我们测量了一组具有相同谐振频率但不同直径 D 的圆柱形管道的声学 Q 值。Q 与 D 的关系图可以很好地拟合两个参数，其中一个参数对应于管道端部辐射产生的能量损失，另一个对应于非常靠近管壁的热损失和粘性损失。无论管道位于何处，壁损失参数都相当恒定，但辐射损失参数随房间内位置的不同而显着变化，这表明房间反射影响了管道辐射的声音。这项研究无需花费太多费用即可提供有价值的见解，并且可以作为高年级本科生实验室实验的基础。
The quality factor Q of a damped oscillator equals 2π times the ratio of stored energy to the energy dissipated per cycle. This makes Q a sensitive probe of energy losses. Using modest equipment, we measured the acoustical Q for a set of cylindrical pipes having the same resonant frequency, but different diameters D. The graph of Q vs D could be well fitted with two parameters, one of which corresponds to energy loss via radiation from the ends of the pipe, and the other to thermal and viscous losses very close to the pipe wall. The wall loss parameter was quite constant no matter where the pipes were located, but the radiative loss parameter varied significantly with location inside a room, suggesting that room reflections affected the sound radiated from the pipe. This study offers valuable insights at no great expense, and could be the basis of an upper-division undergraduate laboratory experiment.