敷设吸声覆盖层复杂目标的目标强度计算

Calculation of Target Intensity for Laying Complex Targets of Sound Absorbing Overlay

提出一种获取非刚性板块元法中反射系数项的方法,来解决复杂目标敷设空腔型覆盖层后目标强度的计算问题。首先计算平面波斜入射条件下覆盖层的反射系数,将其代入非刚性表面目标特性的板块元方法中来计算目标强度;随后分别采用有限元法和该方法求解敷设空腔型覆盖层的刚性球模型,两种方法的计算结果符合较好,此计算方法的有效性得到验证;最后基于该方法计算敷设圆柱型空腔覆盖层的标准潜艇模型。结果表明:0到4 kHz内,随着频率的增大,敷设圆柱型空腔覆盖层的目标强度降低值越大;同一频率下,方位角140度到160度范围内目标强度降低值比其他方位角高一半左右。

A method to obtain the reflection coefficient term in the non-rigid plate element method is proposed to calculate the intensity of the complex target with a cavity overburden.Firstly,the reflection coefficient of the overlay under oblique incident plane wave is calculated,and the intensity of the target is calculated by the plate element method with nonrigid surface target characteristics.Then,the finite element method and the proposed method are used respectively to solve the rigid sphere model with the cavity type overburden.The results show that the results of the two methods are in good agreement,which verifies the effectiveness of the proposed method.Based on this method,the standard submarine model with cylindrical cavity covering layer is calculated.The results show that the reduction value of target intensity with cylindrical cavity covering layer increases with the increase of frequency from 0 to 4 kHz.At the same frequency,the target intensity reduction in the azimuth range of 140°to 160°is about half higher than the other azimuths.