This master’s thesis focuses on the determination of airflow resistance in porous and granular materials and the analysis of their sound absorption characteristics. For this purpose, a custom measurement device was developed and constructed, capable of performing tests according to ISO 9053-1:2020 (steady airflow method) and ISO 9053-2:2020 (oscillating airflow method). Experimental measurements were carried out on different materials (furniture foam, melamine foam, flocked fabric, and sandbox sand), and results were compared with reference data obtained from an impedance tube. The validity of empirical acoustic models, specifically Delany–Bazley and the improved Delany–Bazley–Miki model, was evaluated. The results show that these models accurately predict absorption in classical porous materials, while larger deviations occur when applied to granular media such as sand. The thesis also highlights the limitations of the measurement methods and emphasizes the importance of accurately determining specific airflow resistance as a key input parameter for acoustic modeling.
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