矩形封闭长空间声场的高频计算方法

基于射线跟踪的思想，提出一种矩形封闭长空间声场预测的高频数值计算方法。该方法中只要具备声场空间的边界条件参数，即声场空间长、宽、高和吸声系数，就可以解析计算任何一根声线能量随时间的衰减变化，以及任何一根声线在任何时刻的到达坐标。如果逐一计算每根声线在特定位置的到达时间和声能量，并统计所有计算结果．就可以得到此处的时域脉冲响应，并由此计算声场声压级。该方法不必对声线进行跟踪，省去了建模、入射和反射等射线跟踪计算细节，运算量大为降低，因此计算速度很快。采用实验方法对该算法的性能进行了验证，对长空间中的声场进行测量，将测量结果与本文所提算法的计算结果进行对比，二者吻合很好，证实了该方法的有效性。

Prediction method of sound field in the rectangular long enclosure

A high-frequency numerical algorithm is proposed to predict the sound field in the rectangular enclosures based on the ray-tracing method. In this algorithm, according to some boundary condition parameters such as the length, width, height and absorption coefficient of the sound space, the sound energy of any sound ray at any lime, as well as the three dimensional arrival coordinates of any sound ray at any time, can be calculated. Through calculating the arrival coordinates and sound energy of every sound ray at a certain time and getting the statistical result, the sound space energy distribution at this time can be obtained. Through calculating the arrival time and sound energy of every sound ray at a certain place and getting the statistical result, the impulse response of this place can be obtained. In the new algorithm the sound rays need not be traced, so the calculation time is shortened greatly, and the prediction accuracy is very high. The sound field of a reverberation room with a long enclosure is measured, and compared with the results of the new algorithm. The good coincidence between the two kinds of results verifies the validity of the new algorithm.