锥形颈部赫姆霍兹共振器声学性能预测

The acoustic performance prediction of the Helmholtz resonator with a conical neck

锥形颈部赫姆霍兹共振器具有更好的低频消声能力,而其声学性能尚无准确解析预测方法。为了研究其声学性能,在声学长度修正的基础上,利用一维解析方法建立了用于计算传递损失的一维修正模型。运用分割法计算锥形管内部声传播的声学长度修正,并给出了声学修正长度计算公式。采用得到的锥形管声学修正长度和一维修正模型,计算出的锥形颈部赫姆霍兹共振器频率与有限元及实验测试结果偏差在2 Hz以内,明显优于不修正的计算结果。表明锥形管声学长度修正法提高了一维解析方法的精度,从而可以快捷准确的预测锥形颈部赫姆霍兹共振器的消声性能。

The Hehnholtz resonator with a conical neck, which have broad acoustic attenuation band performance in the low frequency range, have no accurate analytical approach for the acoustic performance prediction. To investigate its acoustic performance, a general theory model based on the one-dimensional analysis approach with acoustic length corrections is developed to predict the transmission loss （TL）. A segmentation method is used to calculate the acoustic correction lengths for the sound propagation in the conical tube. And then, an approximate formula is provided to give correction lengths for conical tubes with different geometries. The TL results obtained by the general theory and the acoustic correction lengths are compared with the results from the finite element method and experiment, which show that the deviations of the resonance frequency are less than 2 Hz and experiment, which show that the deviations of the resonance frequency are less than 2 Hz and much better than the results from one-dimensional approach without corrections. The method of the acoustic length correction for the conical neck, greatly improved the accuracy of the one-dimensional analysis approach, which will be quick and accurate to predict the sound attenuation property of the Helmholtz resonator with a conical neck.