宽频声衬的发展要求在阻抗提取过程中要考虑管道三维声场，而已有的三维阻抗提取方法中普遍将切向流假设为均匀流动，这与实际流管中为剪切流动的情况不符。为了同时解决声衬阻抗提取中的三维声场处理和剪切切向流问题，发展了一种考虑等效一维剪切流的三维阻抗直接提取方法。该方法利用布置在声衬对面刚壁上的矩形测点阵列上的声压数据，首先在展向利用模态分解得到中间变量，再利用龙格-库塔迭代直接求解纵向特征值问题得到轴向波数，最后利用阻抗边界条件得到阻抗。通过基于有限元的数值模拟实验，该方法在平面波和平面波占优入射条件下的准确性得到了验证。通过对是否考虑剪切切向流的阻抗提取结果进行对比，可以发现剪切流虽然在低于截止频率的中低频范围内对阻抗提取影响较小，但是在高频范围内却可能显著影响阻抗提取的精度，并且随着流动马赫数的增加，剪切流的影响愈加凸显。

The development of broadband acoustic liners requires taking the three-dimensional acoustic field into consideration in impedance eduction. However， in existing three-dimensional impedance eduction methods， the grazing flow is generally assumed to be uniform， which is inconsistent with the actual situation of shear flow in flow ducts. To simultaneously solve the problems of three-dimensional acoustic field and shear grazing flow in acoustic liner impedance eduction， a three-dimensional straightforward method considering a one-dimensional equivalent shear flow is developed. Using sound pressure data from a rectangular array of measuring points arranged on the rigid wall opposite to the liner surface， spanwise modal decomposition is firstly conducted to obtain intermediate variables， which can then be solved through Runge-Kutta iteration to compute the axial wavenumber. Finally， impedance is educed according to the impedance boundary conditions. The accuracy of this method is verified through numerical simulation experiments based on the finite element method for both plane-wave and plane-wave dominant incidence. By comparing the educed impedances with and without considering the shear grazing flow， it can be found that although shear flow has a relatively small impact on impedance eduction in the mid to low frequency range below the cutoff frequency， it may significantly affect the accuracy of the eduction result in the high frequency range. Moreover， as the flow Mach number increases， the influence of shear flow becomes more important.