Along the stream line xBAPJ,

ψ = 0,   u = ae−πφ/m;

(13)

and over the jet surface JPA, where the skin velocity is Q,

= −q = −Q,   u = aeπsQ/m = aeπs/c,
ds

(14)

denoting the arc AP by s, starting at u = a;

ch nΩ = cos nθ = √ b − a′ u − a,
a − a′ u − b

(15)

sh nΩ = i sin nθ = i √ a − b u − a′,
a − a′ u − b