High-Speed Waveless Boat

I'm not an engineer. I am a geek, sir.

 

The frictional component of drag will be very large. You cannot avoid that by just saying that water is a good lubricant. You must be able to provide an estimate. Not just for us, but to convince yourself. There are some simple formulas you can use, e.g. the ITTC line to estimate that component.

Sorry, but I don't know what you mean by separation will not overcome the front resistance. When you say "front resistance" do you mean the resistance due to wave-making?

Separation drag can increase the frictional resistance by a factor of 20% or sometimes much more. And that is from each of the three surfaces (hull and 2 duct surfaces).

 

Careful there! I can be as impractical as the next mathematician. One of the low wave drag hovercraft I referred to earlier looked interesting until I calculated that a 76m long vessel made a 36m deep hole under the air cushion.

Every man has an idea that will not work.

Leo.

 

the frictional resistance by a factor of 20% or sometimes much more.
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diffrent speed has diffrent frictional resistance. Usually, frictional resistance is ignored in ship design. 20% frictional resistance may be your are designing a torpedo.

 

allthough i like the nickname "waveless" i dont like reading the above as reply to a first post from a new member. i had to realise and learn these calcs before not so long ago so here the ITTC math for only wetted surface. cf = 0.075/(logRn - 2)**2where rf = 0.5 rho v**2 S Cf and 3 times plm. 20% and and and comes before making newcomers crazy i feel, its a pretty serious forum here ya know as agent for that free deal i ordered a new free mobile phone with a P4 pc as gift to do the maths

 

A pipe D=1.2m. water speed=1000m/s, hydraulic pressure=10m deep, energy loss=0.0016% per meter.

This is the result that find by google.

 

is that one meter tube going trough the water sound barriere?
offcourse there are a few more "and's" to consider

 

If you have a boat, you buy a square meter sheet metal, put into water at side of the boat, run a hour, you will get the result.

 

You are very wrong on this point. Frictional resistance is not ignored in ship design. The 20% I quoted is the additional drag due to form drag.

 

It doesn't work that way. Firstly you need to ensure that the Reynolds number is the same as the vessel's, secondly you need to account for separation and other three dimensional effects.

 

Yes, that is a bit of a worry!

NB Your payments will be delivered by "Flying Robo-Pig".

Leo.

 

help for boat designing

sir can i get more information about your design.pls now am working as a fiberglass engineer.

 

help for designing a boat

sir can i have more details of your design ,pls.

 

sibyjoseph,

I am not a boat design, but I will give you a 3D design of the Waveless Boat, it will help you to construct.

 

I like this project because it's making me think outside the box. It challenges conventional wisdom to an extreme I might add. Cutting down on wake while doubling or tripling surface area. Every calculation making wake a by-product of resistance and resultant drag will have to re-evaluated if you pull this one off.

Perhaps my last offering on this is this: Water is not a better lubricant than air – period.

You might want to look a some of those Russian patrol boats with stepped hulls. They inject pressurized air at the step.

What affect would this have - for propulsion; combine an air jet stream with a water jet stream located all around the inside lower lip of the bow foil opening. This might lower drag, but at the expense of decoupling the water flow from the curved neutral foil. Do you want the water to cling to the hull and produce drag? Do you want the water to decouple from the hull and reduce drag? Is wake always a direct product of drag? I really don’t know myself, just asking.