Flettner

Maiden voyage of the SS Bernoulli, a model Flettner Ship

Category:

Science & Technology

Tags:

• flettner
• ship
• fluid
• mechanics
• magnus
• effect

[emily92japan]

hey! so i have another question to ask you. so i have started my model ship and it is going pretty well except i can't get the tubes to spin perfectly. they just end up wobbling. i was wondering how you attached the tubes to the motors so perfectly?

thanks!

[jassibo]

I had the same problem originally. To fix it, I made solid plastic columns to fit inside the pvc. If you don't have access to a lathe, you may want to try attaching a stabilizer to the top of the tubes in order to prevent the wobble. It could be as simple as a strip of light plastic with two bearings inset in either end. The bearings would then interact with each of the tubes via an axis sticking up from a small plug in the center of each tube. Good luck!

[emily92japan]

So I was thinking about making a flettner ship model for my physics class. I was wondering what kinds of materials you used and what type of electric motor.

[jassibo]

Hi. I had access to a university machine shop so even though I used simple parts, some of the proceedures were complicated. The hull was styrophoam. The masts were pvc tubing with gearing glued to the bottoms and set into cylindrical ball bearings. The motors were each 1.5 mV (from radioshack) with a small axel with gearing on the end.

[PatrikMacGoohan]

The tubes spin on their axis. Through friction they drag along a little air that clings to their exterior. This air gets hit with the air current from the fan. On one side of the tube the fan is pushing air in the same direction that it's moving. The air on that side of the tube will generate lift (horizantal lift), but 180 degrees away the dragged air is hitting the fan air head on. The air current here is slowed. That creates drag. The ship shouldn't go anywhere but the video shows that itdoes

[jassibo]

I was trying to create a model of the Flettner Ship for my fluid mechanics class. Like an aifoil, a zone of slightly lower pressure devlops on the side of the column with the faster wind speed according to Bernoulli's principle. A zone of higher pressure is formed on the side with a lower air speed. The ship is the "sucked" forward due to the pressure difference.

[TETOYVIENDO]

hi!, one question... what will be the effect if the "tubes" have the same little hole of the golf ball???... that will increase the forward speed!?!?! or do smething bad in the performance of the machine!?!?!?!?!

[IneedTodisco]

what is this

[lostinseganet]

How long did it take to cross the atlantic?

[Teratornis]

Did you try putting horizontal disks on the rotors? They should make the rotors work better by reducing spillage from the high pressure side to the low pressure side. See the paper by Salter et al. that I added to the Rotor ship article on Wikipedia (sorry, lame YouTube doesn't let us link in comments).

[arnauchica]

Patrik, sails need a lot of ropes and well made structures to work good. Also, sails must be controlled every time.

A rotor only needs a motor to rotate, and its more efficient than a sail. And leaves more space for the cargo.

[erg0456]

You may want to investigate a physics principle called the Magnus Effect. BTW; the ship Flettner built was called the Baden-Baden. There was another one called the Barbara and there are photos on the internet of both ships.