theo_fun

Returns the value of Theodorsen’s function at a reduced frequency \(k\).

\[\mathcal{C}(jk) = \frac{H_1^{(2)}(k)}{H_1^{(2)}(k) + jH_0^{(2)}(k)}\]

where \(H_0^{(2)}(k)\) and \(H_1^{(2)}(k)\) are Hankel functions of the second kind.

param k

Reduced frequency/frequencies at which to evaluate the function.

type k

np.array

returns

Value of Theodorsen’s function evaluated at the desired reduced frequencies.

rtype

np.array