maxlenz
07-20-2007, 09:59 AM
Aim: Efficient low speed boat for families.
Many agree rowing is not very efficient way of producing forward thrust.
I hate to feel constantly the waves when moving in a boat.
So I constructed a prototype of a vertical fin which has a lift of about 120% of total weight, is soft and waves up to a certain height "overroll" the fins.
First attempts at Wakra-Beach near Doha showed:
1. very stable, no problem to be overturned.
2. slow but impossible to check achievable speed with prevailing constant strong winds due vertical position of "manipulator" giving too much area to the wind.
Lookout:
next prototype:
fins should bend fully elastically as now energy is lost when aluminiumsheet moves against styropor. solution idea: using 5 pane acrylic glass which is soft in one direction and stiff in the other direction.
fins should be transparent to enable watching through them ("glass bottom boat"). no idea of a solution as 5 pane acrylic glass is not transparent enough)
further ahead:
3 units for a plattform 1m above water, powered by electric actuators driven by a solar cell roof.
use for higher speed constructions.
http://home.tiscalinet.ch/hardwaldhexen/mantafish1.jpg
http://home.tiscalinet.ch/hardwaldhexen/mantafish2.jpg
Many agree rowing is not very efficient way of producing forward thrust.
I hate to feel constantly the waves when moving in a boat.
So I constructed a prototype of a vertical fin which has a lift of about 120% of total weight, is soft and waves up to a certain height "overroll" the fins.
First attempts at Wakra-Beach near Doha showed:
1. very stable, no problem to be overturned.
2. slow but impossible to check achievable speed with prevailing constant strong winds due vertical position of "manipulator" giving too much area to the wind.
Lookout:
next prototype:
fins should bend fully elastically as now energy is lost when aluminiumsheet moves against styropor. solution idea: using 5 pane acrylic glass which is soft in one direction and stiff in the other direction.
fins should be transparent to enable watching through them ("glass bottom boat"). no idea of a solution as 5 pane acrylic glass is not transparent enough)
further ahead:
3 units for a plattform 1m above water, powered by electric actuators driven by a solar cell roof.
use for higher speed constructions.
http://home.tiscalinet.ch/hardwaldhexen/mantafish1.jpg
http://home.tiscalinet.ch/hardwaldhexen/mantafish2.jpg