基于解析法的旁支管共振消声带宽计算

Calculation of sound attenuation bandwidth of side branch tube based on analytic method

旁支管是应用广泛的共振消声结构。应用解析方法推导旁支管共振结构的传递损失和共振频率计算公式,考虑三维修正,给出旁支管共振消声带宽与各种参数的定量关系,定义消声带宽与共振频率的比值为带宽参数,研究带宽参数与传递损失以及旁支管其他参数的变化关系,最终给出旁支管共振消声带宽计算公式。最后,通过三维有限元方法(Finite Element Method,FEM)计算旁支管的消声带宽并与文中公式结果进行比较,结果显示,两种结果吻合良好,验证了计算公式的可靠性和准确性。

Side branch tube, as a kind of resonant structure, is widely used to attenuate noise. In the present paper, the transmission loss and resonant frequency expressions of side-branched tube is deduced with analytical approach. Then, the relationship between the attenuation bandwidth and other factors of side branch tube is built quantitatively by considering the three-dimensional correction. The bandwidth factor is defined as the ratio of attenuation bandwidth to resonant frequency. The effects of transmission loss and other factors on the attenuation bandwidth are studied. The final formula of sound attenuation bandwidth of side branch tube is given. Finally, the results calculated with the present formula are compared with the numerical results obtained by three dimensional finite element method; and the comparison shows good agreement and verifies the reliability and accuracy of the present formula.