声学多孔材料的孔结构优化

介绍了一种基于微结构的声学模型,可用来对多孔材料的微组织结构进行优化,从而使多孔材料具备最佳的声学性能.该模型是一种适用于低雷诺数的非稳态线性声学模型,主要微结构考虑平行排列的柱形杆件或圆球列阵,包括3个子模型:①声波传播方向平行于圆柱形杆件的子模型;②声波传播方向垂直于圆柱形杆件的子模型;③声波在圆球列阵中传播和吸收的子模型.前2个子模型通过考虑多边形周期边界条件的影响,计及了相邻圆柱形杆件间的交互作用.由于模型是线性的,因此可以结合起来描述任意角度入射声波的传播特性.第3个子模型可用于描述胞状多孔材料中节点处的情形.文中利用这3个子模型来扩大吸声材料的设计空间,根据不同用途所要求的声学特性计算最优的胞元结构,并对这种模型的应用领域进行了分析讨论.

Microstructural Optimization of Cellular Acoustic Materials

A microstructure based acoustic model is introduced,which can be used to optimize the microstructure of cellular materials and thus to obtain their optimal acoustic property.This acoustic model is an unsteady one which is appropriate in the limit of low Reynolds numbers.The model involves three elements.This first involves the propagation of acoustic waves passing the cylinders whose axes are aligned parallel to the direction of propagation.The second model relates to the propagation of acoustic waves passing the cylinders whose axes are aligned perpendicular to the direction of propagation.In both cases the interaction between adjacent cylinders is taken into account by considering the effect of polygonal periodic boundary conditions.As these two models are linear they are combined to give the characteristics of propagation at arbitrary incidence.The third model involves propagation passing spheres in order to represent the joints.Heat transfer is also included.These three models are then used to expand the design space and calculate the optimum cell structure for desired acoustic performance in a number of different applications.Moreover,the application fields are also analyzed.