Use the Line Source on Axis node to add a line source on the axis of symmetry in 2D axisymmetric components. This type of source corresponds a radially vibrating cylinder in the limit where its radius tends to zero. The line source adds a source term to the right-hand side of the governing Helmholtz equation such that:

where is the delta function in 3D that adds the source on the axis of symmetry where z = z0 and r = 0, and dz is the line element along the z-axis (SI unit: m). The monopole amplitude S (SI unit: N/m2) depends on the source type selected and is the same as discussed in the 3D case for a Line Source.

Select a Type: Flow (the default), Intensity, Power, or User defined. See the options and expression for Line Source. The sources are the same but in 2D axisymmetric components they are only applicable on the symmetry axis at r = 0.