New propulsion sytems for ships

brian eiland · Feb 23, 2010

Exciting New Fuel Cell Technology...the Bloom Box

I gave this subject its own new subject thread as it just might be that exciting to justify it:

Bloom Box energy cell

http://www.boatdesign.net/forums/propulsion/bloom-box-revolutionary-new-fuel-cell-technology-31618.html#post346856

Guillermo · Feb 24, 2010

Mmmmm, let's wait to know any real eficiency data.
Cheers.

The copper guy · Feb 24, 2010

Shipping Has Always Tried To Carry More For Less!

cyclops said: ↑

They will always find the cheapest setup and use it. Forget changing them. They are registered in countries that care less than nothing.
Click to expand...

WE ALL WONT THE CHEAPEST and they will jump at anything cheaper than oil,
already they are running on reduced revs to save on expensive fuel.
If we the end users can provide an alternative transport method? there is no doubt the shipping companies will jump at the opportunity.

Guillermo · Feb 25, 2010

Here the revealed solid oxide fuel cell:
http://www.bloomenergy.com/

The web site is a nice marketing hype, but they talk about savings without providing numbers to corroborate...mmmm...

FAST FRED · Feb 26, 2010

"already they are running on reduced revs to save on expensive fuel."

Actually for most it is a big process to "run on reduced revs" as the hull and drive setup are designed as a package.

It is about 1/2 million US to change the bulbous bow to one that is efficient at the slower speed .

Then of course there are prop and propulsion engine modifications to pay for.

No free lunch just with the throttle.

FF

Guillermo · Feb 26, 2010

Not always are things like that, implying substantial modifications, Fred. In fact they are just slowing down:

http://www.treehugger.com/files/201...fleet-cuts-fuel-use-30-percent-half-speed.php

http://www.fao.org/docrep/x0487e/x0487e03.htm

http://www.futurefuelsme.com/news/2008/news_08_074.html

etc, etc.

Cheers

masrapido · Mar 2, 2010

These cells may be efficient, but are still too big. Look at the dimensions. For a decent power you would need a container ship just to store the cells.

They would need to be miniaturised significantly to reach diesel's power-to-volume ratio.

powerabout · May 14, 2010

Last year Maersk altered their timetables to reflect the new slow speeds.

Tsen66 · Aug 10, 2023

Guillermo said: ↑

Sweep

The USA engineer Don Burg (President of Hydro-Air Drives, Inc.) has patented a new concept of ship called SWEEP (Ship with Wave Energy Engulfing Propulsors).
http://www.linkgrinder.com/Patents/Ship_with_wave__7017505.html
"Abstract: Presented is a water propulsion system for ships that enhances the efficiency of both the water propulsor(s) and the ship itself. This is accomplished by location of water inlet(s) for the water propulsor(s) to take advantage of water flow characteristics around a secondary bow of the ship and also proximal a stern of the ship. A primary object is to reduce the energy of the bow and/or stern waves of the ship and hence reduce the ship's wave making resistance. A secondary object is to reduce the frictional resistance of the ship. The water propulsors are preferably electrically driven with built in stator field windings and armatured rotors. A bow oriented water propulsor(s) would preferably have its discharge into a gas cavity in the underside of the ship. Both bow oriented and stern oriented water propulsor(s) would optimally have steering and/or reversing mechanisms."

It significantly reduces the wave drag of high-speed displacement hulls by utilizing the inlet water flow into large water propulsors to engulf or suck in wave energy. The water flow detaches from the sphere at the bow in high drag eddies after following the contour of the sphere inward aft of the sphere's mid-section. In order to maximize its efficiency gains an optimum SWEEP discharges its bow propulsors water jet flow into a raising air layer under the hull. This approach avoids turbulence-mixing losses that would occur if the discharge jet was underwater. The blower power required to maintain the SWEEP's presurized air layer is only a few percent of its propulsive power. (Burg D. Work Boat World 2005 24/8, 20-21)

Following Don Burg's data, a 122 m long SWEEP ship reduces its total resistance between 15 and 20% at 20 knots and 40% at 45 knots.

More:
SWEEP (Ship with Wave Energy Engulfing Propulsors) has been the subject of presentations at ASNE (American Society of Naval Engineers) Day 2005, FERRIES 2005, and is the subject of articles in Naval Engineers Journal and other trade publications. The SWEEP invention promises to improve the efficiency of large high speed displacement hulls such as destroyers and larger military combatants, high speed freighters, and the like. It is the subject of a proposal for government funding by the Military SeaLift Command (MSC) and the Naval Surface Warfare Center (NSWC).
Click to expand...

Don Burg was an amazing person to know.

fredrosse · Oct 8, 2023

"No free lunch just with the throttle."

Is that so? According to my training there is a huge saving in fuel with just the throttle. For displacement hulls. maybe not the exactly optimized propeller, or engine conditions, or bow configuration, but still the biggest bang for your buck is to just back off the throttle/RPM wih the basic cubic speed-power relationship.

Log in or Sign up

New propulsion sytems for ships

brian eiland Senior Member

Guillermo Ingeniero Naval

The copper guy Junior Member

Guillermo Ingeniero Naval

FAST FRED Senior Member

Guillermo Ingeniero Naval

masrapido Junior forever

powerabout Senior Member

Tsen66 New Member

fredrosse USACE Steam

Propulsion for a 36ft aluminum boat

Bio Inspired Propulsion

Wave force induced power proa magnetic propulsion

Best Propulsion system for my boat

Article on Waterjet propulsion

Propulsion general questions for heavy use on 30ft power cat.

Yachting propulsion systems

Magnus effect for ship propulsion

Putting this out there for discussion (livaboard river boat propulsion)

Conytrapel Propulsion