Room acoustic simulations usually assume the acoustic impedance of surfaces to be independent from wave incidence angle – in other words locally reacting. For most materials this is a valid assumption. Some porous absorber structures are, however, non-locally reacting: Their surface impedance expresses a dependence on the direction of an incident wave – more exactly on the elevation angle. Still, it can be useful to allocate an angle-independent representative impedance value to the material surface in order to simplify the simulation significantly at the cost of a manageable error. It is common practice to take the impedance at normal incidence or the impedance experienced in a uniform distribution of directions (diffuse field) as this representative value – all yielding non-negligble errors. This thesis tries to improve on previous methods by finding a representative impedance that takes into consideration the true incidence angle distribution experienced by a porous absorber in a real environment. With a theoretical construction of the incidence angle distribution and the definition of an effective impedance, small improvements are achieved in numerical simulations of an oversimplified room geometry.

Melden Sie sich hier an um Einladungen zu den Kolloquium-Vorträgen per E-Mail zu erhalten.
Register here to receive the invitations to colloquium talks via e-mail.

Zoom-Meeting-ID: 954 4073 3814
Passwort: 450783