High-Speed Waveless Boat

Airboats are not hovercraft.............story of my life explaining the difference - and there are many.

Hovercraft are not "displacement craft". That is to say they do not displace water to achieve buoyancy. They hover on a cushion of pressurized air contained at the sides by a flexible curtain known as a skirt. The air leaks out the bottom, which in affect air is the lubricant allowing the craft to slide along the surface. This is why the French call them "air sliders".

Once an airboat (or aeroboat) gets up to speed they don't create much of a wake, but they are still a displacement craft. Airboats are boats, however hovercraft are registered as watercraft in the United States.

Confused yet?

Ever play air-hockey?

 

Once an airboat (or aeroboat) gets up to speed they don't create much of a wake, but they are still a displacement craft.
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that is correct, and the component of forces of hovercraft will generate wave too.

 

I also have designed a high-speed submarine that is like a dolphin, the dolphin submarine can flying on the surface of the water, and dive into the water. it can glide under water and drive by batteries. the principle of the dolphin-submarine is same as waveless boat, it have a long fin out of the water. if I have time, I will draw a 3D model here.

 

A bathtub-size model is probably not big enough. At that scale surface tension will wipe out high-frequency (diverging) waves which is where most energy is going at high Froude numbers.

 

This is one of my bookmarks on my computer, you might want to look at it.

http://www.innespace.com/

 

That's the most intelligent thing anyone has said on this thread.

I'll let you take over now.

I'm no engineer, I bow to your expertise.

 

Strictly speaking, Michlet is not a CFD code. Thanks for your promotion though - you can have 10% as an agent's fee.

 

A bathtub-size model is probably not big enough. At that scale surface tension will wipe out high-frequency (diverging) waves which is where most energy is going at high Froude numbers.
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I am a computer engineer, no ability to do the test. I think that is posible to solve the problems by changing the size and speed of the screw, and also can fix the screw prop to the middle of the boat.
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High-Speed Waveless boat is my dream, she will come to the world.

 

There might be some advantages such as better inflow to the prop, but I doubt that you will get a large decrease in wave resistance and wave-making. Don't let that stop your experimentation though!

Some of my ideas for wave wake reduction can be found at:
www.cyberiad.net/wakeimages.htm

See "Weinblum" and "Tetrahull Animation".

Good luck!
Leo.

 

RE: www.cyberiad.net/wakeimages.htm

Great, loved it..............will you ever do images for Hovercraft and Hyrofoils?

 

You can find some images of very low wave resistance "hovercraft" in a paper I co-authored at:
www.cyberiad.net/pd.htm

There are more images in "Wave patterns and minimum wave resistance for high-speed vessels":
www.cyberiad.net/wakepredict.htm

Your "dolphins" are delightful. Can they sense when there is trouble at the mill, or that Gramps is being held hostage by bearded ruffians?

Leo.

 

Beautiful, thanks.

I'm not getting access the full user's manual for Michlet Version 8.05. Do you have any tips other than what's in the instructions? Only 1 of the 16 catagories is working for me.

 

I'm not sure what you mean. I just downloaded the file myself and unzipped it. When I load the file "michman.htm" into my browser I get the index to 16 sections. Each section can be accessed by clicking on the appropriate line in the index.

Leo.

 

Time to call in the computer guy across the hall then. Thanks for checking it out for me. Cheers George/kach22i.

 

My pleasure.

Please keep in mind that Michlet is not an easy program to use. And be sure that you really need to calculate the drag for whatever project you are embarking on.

All the best,
Leo.