Jet Pipe

Model ID: 1844


This example models the radiation of fan noise from the annular duct of a turbofan aeroengine. When the jet stream exits the duct, a vortex sheet appears along the extension of the duct wall due to the surrounding air moving at a lower speed. The near field on both sides of the vortex sheet is calculated.

The Aeroacoustics modeling interface in the Acoustics Module describes acoustic waves in a moving fluid. However, the field equation is only valid when the velocity field is irrotational, a condition that is not satisfied across a vortex sheet. As a consequence, the velocity potential is discontinuous across this sheet and to model this discontinuity, you use assemblies that are connected through coupling pairs.