Circular Source (for 2D Axisymmetric Components)
Use the Circular Source node to add a source in a 2D axisymmetric component on points off the axis of symmetry. Such points correspond to circular sources or ring sources. This type of source is, for example, used to mimic source terms from rotors. The circular source adds a point source term to the right-hand side of the governing Helmholtz equation such that:
where is the delta function that adds the source at the point where x = x0 and rdϕ is the line element around the circular source (SI unit: m). The monopole amplitude S (SI unit: N/m2) depends on the source type selected, as discussed below.
For the Pressure Acoustics, Transient interface the Flow (no phase specification), User defined, and the Gaussian pulse source types are available. The Gaussian pulse source type has no effect in the frequency domain. See The Gaussian Pulse Source Type Settings.
Circular Source
Select a Type: Flow (the default) or User defined. For User defined enter a Monopole amplitude, S = Suser (SI unit: N/m2).
Flow
When Flow is selected the source is defined in terms of the volume flow rate QS per unit length out form the source. The flow circular source defines the following monopole amplitude:
Enter values or expressions for:
•
Volume flow rate per unit length out from source, QS (SI unit: m2/s).
•
Phase (SI unit: rad).