基于阻抗管和流管试验平台，试验研究了适用于叶顶声衬和软静子的大厚度穿孔板在无切向流条件和存在切向流条件下的声阻抗特性，并探讨了北航模型对大厚度穿孔板声阻抗预测的适用情况。在无切向流条件下，厚度为8mm的实心穿孔板的试验声阻抗表现出了良好的线性特征，并且北航模型能够准确预测大厚度穿孔板的声阻抗。同时，针对静子叶片为中空结构的情况，提出了蜂窝腔夹层穿孔板结构。测量结果表明，该结构的声阻抗主要由两侧的穿孔板提供，中间的蜂窝腔仅提供少部分的声抗。在存在切向流条件下，从声阻抗预测准确性和传递损失两方面研究了北航模型对大厚度穿孔板声阻抗预测的适用情况。当切向流流速为10m/s和20m/s时，北航模型仍然能够准确预测大厚度穿孔板的声阻抗。随着切向流流速的增加，板厚对小孔内涡脱落的影响开始变得明显。当切向流流速为40m/s和60m/s时，基于薄板涡脱落强度拟合而来的北航模型对大厚度穿孔板声阻抗的预测误差开始变大。但从传递损失上来看，北航模型预测声阻抗的传递损失曲线与试验测得的传递损失曲线表现出了相似的趋势。可见，北航模型对大厚度穿孔板的工程应用仍然具有一定的指导作用。
Based on the impedance tube and flow tube test platforms, the acoustic impedance characteristics of large thickness perforated plates suitable for over-the-rotor liner and soft vans are experimentally investigated in the absence and pres-ence of grazing flow, and the applicability of the Beihang model to the prediction of acoustic impedance for large thick-ness perforated plates is explored. Under the no grazing flow condition, the test acoustic impedance of a solid perforated plate with a thickness of 8 mm shows good linear characteristics, and the Beihang model is able to accurately predict the acoustic impedance of the large thickness perforated plate. Meanwhile, a honeycomb-cavity sandwich perforated plate structure is proposed for the case where the static blade is a hollow structure. Measurement results show that the acous-tic impedance of this structure is mainly provided by the perforated plates on both sides, and the honeycomb cavity in the middle provides only a small portion of the acoustic impedance. In the presence of grazing flow conditions, the applicabil-ity of the Beihang model to the prediction of acoustic impedance for large-thickness perforated plates is investigated in terms of both acoustic impedance prediction accuracy and transmission loss. When the grazing flow velocity is 10m/s and 20m/s, the Beihang model is still able to accurately predict the acoustic impedance of large thickness perforated plates. As the grazing flow velocity increases, the effect of plate thickness on vortex shedding in small holes begins to become apparent. When the grazing flow velocity is 40m/s and 60m/s, the prediction error of the Beihang model based on the fitting of vortex shedding strength of the thin plate on the acoustic impedance of the large thickness perforated plate starts to become larger. However, in terms of the transmission loss, the transmission loss curve of acoustic impedance predicted by the Beihang model shows a similar trend with that of the experimentally measured transmission loss curve. It can be seen that the Beihang model still has a certain guiding effect on the engineering application of large thickness perforated plates.
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