Vortex shedding from a circular cylinder

Vortex shedding mechanism from a circular cylinder. Experimental flow visualisation with hydrogen bubbles and a laser sheet in a water channel. By Gustavo Assi, London, March 2008.

Category:

Education

Tags:

• fluid
• mechanics
• vortex
• vortices
• shedding
• viv
• cylinder
• assi
• imperial
• hydrogen
• bubbles
• flow
• experimental
• water
• laser
• engineering
• physical
• science

[rajkjam]

Hi Gustavo. That's a very very impressive visualization indeed.

I wonder what the strength (amperes) of current and/or the voltage needed to produce this neat stream of hydrogen bubbles is. And, I think the bubbles are being produced intermittently and continuously. What is the time between two electric pulses in this case ?

Thanks.

[gutoassi]

Hi,

I used four stainless steel wires... about 600mm long. The DC power supply was set to 60V, but you must have some control in order to cahnge the rate the bubbles are formed. You need small bubbles that will follow the flow, but still big enough to generate nice traces. There was no need to add salt in the water... London water is very hard already...

Cheers,

Gustavo

[bresslau]

I missed some music too... hehe. But great work, Guto!

[gutoassi]

hehehe... soundtrack for you, Bress...

[imdbstar]

fantastic!!!!

[slump75]

I have no understanding of this and yet I watched it twice. Very interesting things are just very interesting, I suppose.

[Slokos1]

Hey does anyone know how this is made/ set up can someone provide me with a link or something on how to make something like this for a presentation. i understand the basic "materials" he used to do this but I'm curious as to how its built/ operated. Any help would be appreciated.

[Brad1711]

Hmm I loved doing these labs.

[curva130r]

I love it!!!

Thanks for make it and upload it!!!

[xxlegolas]

Very cool means of visualizing the paths the gas bubbles are taking. It's like the next evolution of using a wind tunnel to study drag forces.

[tracksidetuning]

Este video foi uma bastante ajuda. Tava querendo ver como funciona uma Karman sensor num carro. Isso explica perfeitamente em minha mente. Obragado. Tambem este musica é mesmo sientifica. Haha

[kronicred]

this music is making vortexes... in special places.

[bsanderse]

that's a very nice visualization. did you also do quantitave measurements, and publish in a journal?

[rajkjam]

Dear Gustavo. Thanks indeed for replying.

1. Is (60 V) voltage the only criterion or can we work with lesser voltage that can produce sufficient "ELECTRIC CURRENT" to cause electrolysis of water ?

2. Where were the four 60 CM wires positioned in yr visualization experiment ?

Regards.