acdecom.WaveGuide.get_eigenvalue_circular

WaveGuide.get_eigenvalue_circular(m, n, **kwargs)

Returns the eigenvalue of the (m,n)-mode for a circular duct.

\[\kappa_{mn} = \frac{R_n(J'_m)}{r}\]

where \(J'_m\) is the derivative of the Bessel function of first kind and order m, and \(R_n\) is the n-th zero.

Parameters

• m (int) – Mode-order in the circumferential direction. The plane wave has the order 0.

• n (integer) – Mode-order in the radial direction. The plane wave has the order 0.

• kwargs (additional arguments) –

Returns

The eigenvalue of the (m,n)-mode, divided by the radius.

Return type

float or complex