design concept

[seadragon]

The full displacement hull have a D/L of 1.34 for max speed in general, any speed that is higher will consume a lot of power. If we channel the water from both sides of the boat/ship at the bow to propeller. The benefit of doing this will be, reduces wake create by the hull, also reduce the water resistance of the hull moving forward. Of course, that means better D/L ratio and less power to move the vessel forward. What do you think

[Skippy]

Sounds like a sea sled.

[jehardiman]

Doesn't work well for a number of reasons and has been tried before. But also that ratio of V (not D)/L of 1.34 is only the approximate first wave making hump (distribution of displacement will change it), and not connected to an absolute maximum speed at all.

1) Wave making is a function of dispacement as well as length, and of little concern in small craft that have enough power to get over the hump.

2) Total resistance of a hull that can power over the first hump is more a function of wetted surface and displacement than length and this type of design has more wetted surface (displacement being equal).

3) Greater inflow velocity to the propeller/pumpjet means lower propeller/pumpjet efficency. This is because the skin friction losses on the blades are higher no matter how you generate thrust. This leads to more power required for a given displacement...more fuel...more displacement...more power...etc