Sound from Turbulent‐Boundary‐Layer‐Excited Panels

The directivity of the sound radiation from panels and openings.

This paper presents a method for calculating the directivity of the radiation of sound from a panel or opening, whose vibration is forced by the incidence of sound from the other side. The directivity of the radiation depends on the angular distribution of the incident sound energy in the room or duct in whose wall or end the panel or opening occurs. The angular distribution of the incident sou...

Sound Image Localization on Flat Display Panels

Optimised sound absorbing panels with quarter-wave resonators

The viscothermal wave propagation of the air inside the resonators is efficiently described by the so-called low reduced frequency model. Using this model, absorption coefficients can be calculated for different configurations. The theory has been implemented together with an optimisation algorithm, so that the dimensions of the resonators can be optimised to satisfy any desired absorption leve...

Active/Passive Control of Sound Radiation from Panels using Constrained Layer Damping

Architectural freeform structures from single curved panels

The problem of covering a freeform surface by single curved panels can be treated with the concept of semi-discrete surface representations, which constitute a link between smooth and discrete surfaces. A surface composed from developable strips (called a D-strip model) is the semi-discrete equivalent of a quad mesh with planar faces, or a conjugate parametrization of a smooth surface. Using re...