This paper focuses on quasi-two-dimensional integral surface method in order to estimate the propagation of two-dimensional acoustic waves. In this approach, the required surface data is generated by replication of a two-dimensional data curve along the third out-of-plane dimension. For this purpose, a two-dimensional monopole acoustic source is employed and the Farassat integral surface approach is implemented. It is observed that the estimated sound pressure at far-field converges to the two-dimensional solution as the number of replications increases. The convergence trend shows an oscillatory behavior in terms of replication length and amplitude decay in each cycle. The impact of different parameters such as frequency of acoustic waves, free stream Mach number, distance, and the location of observer on convergence trend is investigated. Based on these results, a methodology to specify the replication length for the required level of convergence is proposed. The capability of the developed method is investigated by studying the cavity flow noise. The estimated noise at far-field for two oscillation modes, namely shear-layer and wake mode, reveals an error of 3.1% and 2.8% in comparison with the reference values, respectively, which indicates that the presented method is capable of predicting the far-field noise with a very good accuracy.

为了估计二维声波的传播，本文重点研究了准二维积分面方法。在这种方法中，所需的表面数据是通过沿第三个平面外维度复制二维数据曲线来生成的。为此，采用二维单极声源并实施 Farassat 积分表面方法。观察到随着重复次数的增加，远场的估计声压收敛到二维解。收敛趋势在每个循环中的复制长度和振幅衰减方面显示出振荡行为。研究了声波频率、自由流马赫数、距离和观察者位置等不同参数对收敛趋势的影响。基于这些结果，提出了一种为所需收敛水平指定复制长度的方法。通过研究腔体流动噪声来研究所开发方法的能力。两种振荡模式（即剪切层和尾流模式）在远场的估计噪声与参考值相比分别显示出 3.1% 和 2.8% 的误差，这表明所提出的方法能够预测远场-具有非常好的精度的场噪声。