计算水下凹面目标散射声场的声束弹跳法

A shooting and bouncing beams method for calculating the acoustic scattering field of concave targets

为了解决含有多次散射时水下目标声散射场的计算问题,提出了一种声束弹跳方法。把入射声波划分为若干声束,根据几何声学方法计算每条声束在目标表面的反射方向和能量损失,利用物理声学方法计算最后一次反射的声束所对应的面元的散射场,通过计算所有声束产生的散射场的叠加得到整个目标的散射场。计算了直角凹面圆锥体的散射声场,并对具体模型进行了水池测量实验,理论计算和实验测量结果一致。表明该方法作为一种高频近似的数值计算方法,可以计算存在多次散射时水下目标的散射声场。

A shooting and bouncing beams method is proposed, which is able to predict the acoustic scattering field when the sound beam is reflected on the concave target surface more than once. Incident sound field is divided into some sound beams. The direction and transmission loss of every sound beam is calculated based on geometrical acoustic method, and the acoustic scattering field of the last reflection beam＇s planar element are calculated based on physical acoustic method. The superposition of all beam＇s scattering field is the target＇s scattering field. Scattering field of orthogonal concave cone was calculated using shooting and bouncing beams method and measured in water tank. The comparison with both the results of calculation and experiment has been found satisfactory. As a high-frequency approximate numerical method, the shooting and bouncing beams method can be used to calculated acoustic scattering field including multiple scattering.