周期结构表面散射系数测试及修正方法

Measurement and correction method for the surface scattering coefficient of a periodic structure

无规入射散射系数是描述结构声反射特性的重要参数,在周期结构等典型扩散体的声学设计和室内声场模拟中具有重要的作用。本文给出了混响室法测试无规入射散射系数的原理,对半圆型周期结构进行了实验测试,并针对测试中存在的缺陷,提出了一种考虑空气间隙吸声的修正方法,经验证具有较好的修正效果。

Random-incidence scattering coefficient is an important parameter to describe the property of sound reflection on the surface of a structure. This coefficient shows its great importance in the acoustic design of typical diffuser such as periodic structure and the indoor sound field imitation. This paper presents the measurement theory of the random-incidence scattering coefficient by the reverberation chamber method. And the coefficient of a sine periodic structure was measured. Considering the defect of the measurement, a correction method was proposed and it is demonstrated to be effective.