Installation manual

Simrad PI Catch monitoring system / Trawl hydrophone
4
851--164472 / Rev.B
Boundary water layers:
(A) = Turbulent flow
(B) = Laminar flow
(C) = Air bubbles in the water
Air bubbles may also be introduced into the boundar y layer. If
the vessel’s hull has little flare and is relatively narrow, bubbles
may escape to the sea surface without incident. On the other
hand a wide, flat hull with minimal deadrise is prone to trapping
air bubbles no matter how little flare it has. Regardless of a
vessel’s hull form, hydrophones are generally recommended to
be installed on the forward part of the hull to minimising the
influence of both turbulence and air bubbles.
Bulbous bow
The bulbous bow may be an acceptable hydrophone location.
Should this position be chosen, t he foremost part of the bulb is
often best, but also the m ost susceptible to pounding.
Recommended location of the hydrophone on a bulbous hull:
(A) = Thruster
(B) = Hydrophone location