Prediction of sound absorption of a periodic groove structure with rectangular profile

Sound absorption of a periodic groove structure with rectangular profile is studied in this paper. On the basis of De Bruijn’s theory, by conducting matrix manipulation in MATLAB, a good prediction of the sound absorption of a periodic groove structure is obtained. Experiments in the Kundt’s tube are carried out and the results match the calculation well. This series of experiments and computation show that with the same period and the same ratio of absorber, groove structures have a much better sound absorbing ability than flat surface structures. Besides, a parametric survey has been done on the performance of the periodic groove structure and porous absorber as well. The parameters are the period of the surface, the ratio of the absorber, the depth of the groove, and the thickness, the flow resistivity, the open volume porosity and the structure factor of the porous absorber. Based on this survey, a periodic groove structure, as well as the porous absorber, with required sound absorbing capability can be created by arranging these parameters suitably.