摘要
根据水平分层介质的物理模型,分别以追求单一频率条件和给定频段条件下反射系数最小为目标,利用遗传算法对不同组合方式的水平分层介质的参数进行了优化。利用遗传算法的随机搜索特性,得到多组不同的物理参数。利用这些参数,对反射系数与结构及材料参数的依赖关系进行了分析。计算了分层结构中每一层的吸收贡献率,提出了阻抗比系数的概念。通过对比,分析了在不同频率条件下,不同水平分层结构对垂直入射平面波的吸收机理。对利用水平分层复合结构材料制作吸声障板可能达到的指标做了进一步的分析。结果表明,为得到较大的吸收系数,不同层间的阻抗比系数必须保持一定关系。
According to the physical model of the horizontal layered media, in order to minimize the reflection coefficient, under respectively the conditions of single frequency and given bandwidth, parameters of the horizontal layered media with different combination styles are optimized by the genetic algorithm. On utilizing the stochastic-searching property of the algorithm, many sorts of combinations of physical parameters can be obtained. Making use of these parameters, the relation between the reflection coefficient and the structure and physical parameters is analyzed. The absorption contribution ratio of each layer in the layered structure is computed and a novel concept of impedance ratio coefficient is introduced. By comparison, the mechanisms of absorption of various layered structure of a vertical incident plane wave of different frequency, is analysed, and the possible absorption property of sound baffle using horizontal layered multiple structure of selected materials discussed. The result is that each impedance ratio coefficient should be kept at certain relation with the others in order to attain higher absorption coefficient.
出处
《应用声学》
CSCD
北大核心
2010年第2期100-108,共9页
Journal of Applied Acoustics
关键词
水平分层
复合障板
物理参数
声学性能
Horizontal layers, Composite baffle, Physical parameters, Acoustical performance
