What's the most efficient propulsion system to transfer engine power into water?

Question

Is it propellers? Paddles? Mississippi-Steamer type wheels? Some bionic design, emulating penguin's feet? I'm trying to find the implement which will translate the highest percentage of the horsepower I produce with whatever means (muscle power, electric motor, diesel, who knows) into propulsion in the water.

It's for a boat project. I want to build my own boat, and I want to build the most efficient, possible drivetrain for it.

Thanks!

Answer 1

propeller.

I'm a big believer in evolutionary theory. Motor boats have been around for quite some time, and many possible solutions have been tried (paddles, wheels, jets, propellers, etc.). People have always wanted to go faster, and use as little fuel as possible.

If today most boats use propellers, it must be because they are the most efficient and economic means of propelling a boat through water.

A

Answer 2

Well Weirdo,

I guess you would first have to look at nature. The fastest propelled things in the water are Porpoises. That, however, would make a really crappy boat design, flipping to and fro and such.

Next, look at what the government uses in their military. The two fastest and most efficient seem to be "Hover Craft" and "Jet". The Jet system is used mostly in submarines but I have seen it used in pleasure craft in conjunction with propellers. The Jet system is my favorite. It uses a screw to intake water and propell it out through the rear of the vessel. A little expensive, but in water it probably causes the least amount of drag.

The Hover system is my second favorite. Less drag than the screw and was even able to move huge loads (260 tons) of building material and trucks across the Yukon river (2.5 miles) in Alaska during the building of the Trans America Pipeline during the 1970's

Hope this helps,

James in San Diego

Answer 3

Water jet is the most economical for a boat at present,
but the most efficient propulsion in water is the one used by the fishes and water mammals like the dolphin's.
So I would recommend that you find out how to put a water jet motor into a boat. First find out how they work.

Answer 4

water jet.
and an electric motor is much more efficient than infernal combustion because you can get one with maximum torque at 0 reves, and moving water takes torque, without complicated gearbox.

Depending where you are using the boat, being quiet and smell free, no fuel spillage, and no exposed moving parts to catch wildlife is a definie advantage too.

However paddling a kayak is probably the most efficient method.

Answer 5

Good question. A screw propeller is pretty efficient. Modern ones are designed by computer to minimize drag and maximize efficiency. Also the material should be smooth to minimize friction with the water.

Answer 6

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Answer 7

Use an off the shelf boat propeller.
The design of these units has been refined for the past hundred years using all the technology available to mankind.

Answer 8

Water jet.