Recent Highlights on the Parallel Transfer Matrix Method (Ptmm)

International audience; Recently, an extension of the transfer matrix method (TMM) to calculate absorption coefficient and transmission loss of acoustic systems in parallel (one next to each other and not one after the other) has been published [1]. This method (P-TMM) is based on the continuity of flow and pressure on each side of the stack. To comply with these constraints, assumptions must be set: there is only plane waves that propagate, no exchange is allowed between the elements of the stack, the stack is smaller than the wavelength. Further progress has been made. Firstly, a comparison with the method of the sum of admittances (ASM) [2] will be presented. Then, a further extension of…