Radiation from Stacks and Chimneys
When modeling stacks and chimneys two radiation components are of relevance:
-
The sound emitted by the chimney’s opening („mouth“) is modeled by a point source located at this height with a corresponding directivity.
-
The radiation by the chimney’s cylinder can be taken into account by a vertical line source - for reasons of simplicity with uniform radiation - located at the chimney’s axis.
Both cases are discussed in the following.

Sound radiation by the chimney’s opening and by the cylinder itself