Optimizing the Shape of a Horn

Application ID: 4353

A plane-wave mode feeds an axisymmetric horn radiating from an infinite baffle toward an open half space. The radius of the waveguide attached to the horn throat is assumed to be fixed, as well as the depth of the horn and the size of the horn mouth attached to the baffle. By varying the curvature of the initially conical neck of the horn, its directivity and impedance can be changed.

This model shows how to apply boundary shape optimization to an axisymmetric horn. For the sake of simplicity, the far-field sound pressure level is maximized for a narrow frequency band and in a single direction. The focus is on the optimization procedure, which involves choice of objective function, and optimization solver settings.

The results from this analysis shows that by changing the shape of the horn within the limits of the selected parametrization, the on-axis sound pressure level can be raised by about 1 dB compared to the simple cone. The optimal shape with respect to on-axis SPL however leads to deep undesirable minima in other directions.

This model example illustrates applications of this type that would nominally be built using the following products: