(10)
The velocity q is zero in a corner where the hyperbola β cuts the ellipse α; and round the ellipse α the velocity q reaches a maximum when the tangent has turned through a right angle, and then
| q = Qea | √(ch 2α − cos 2β) | ; |
| sh 2α |
(11)
and the condition can be inferred when cavitation begins.
With β = 0, the stream is parallel to x0, and
φ = m ch (η − α) cos ξ
= −Uc ch (η − α) sh η cos ξ/sh (η − α)
(12)
over the cylinder η, and as in (12) § 29,
φ1 = −Ux = −Uc ch η cos ξ,