On the Diffraction of Sound Waves by Grilles or Networks of Obstacles

A general study has been made of the diffraction of waves by groups of obstacles regularly dispersed in space. A method is proposed which can be applied to groups of obstacles and is unchanged in the course of one or two translatory movements or again in the course of one or two rotations. It consists of superposing, with the aid of summation formulae, the waves reflected individually by the various obstacles. It is shown that these waves can be determined by solving a system of algebraic linear equations of an infinite order. Two examples are given of these applications.