Page 34 – The Kort Nozzle
The Kort Nozzle is a certain
way of increasing the speed of the boat by about 10%
It
improves the efficiency of the propeller.
The blade of
the propeller pushes water away and behind the boat.
The
water flows onto the leading edge of the blade and the middle of
the blade pushes
the water back and away.
Some water
will escape and slip off the trailing edge of the blade.
Also,
some water will escape and slip off the outer edge of the
blade.
If the outer edge of the blade is encased in a
tube, then water cannot escape in that direction.
This
unwanted flow – and energy waste – is prevented.
The
efficiency of the propeller is increased.
Why aren’t
Kort nozzles fitted to all boats?
Because it only works for
boat speeds below 11 or 12 mph.
Thereafter the drag generated
by the nozzle outweighs the efficiency gain.
So tow
boats, and tugs very often use Kort Nozzles
And how about
inland water craft which are limited to 5 mph?
