Non Newtonian Fluids

This is in preparation of Science Festival 2013

Event: ScienceFestival2013

Application

What to send in

• what we do
  • experiments with corn starch

• what we need
  • water
  • if possible flat floor (water tends to flow downhill)
  • cleaning possibility for the public
  • TV screen for showing videos

Ideas

NOT:

• The classic run over the pool setup is well known and will produce a lot of mess. Also it needs a big quantity of liquid.
• NEWS!!! after inquiry with the organizers, the pool will be done!

YES:

Experiments to be done on tables showing the different properties. Flowing, vibration, impact.

• On a speaker cone, see http://www.youtube.com/watch?v=3zoTKXXNQIU
• The Weissenberg effect, see http://www.youtube.com/watch?v=npZzlgKjs0I
• The Kaye effect, see http://www.youtube.com/watch?v=GX4_3cV_3Mw

Science?

• Build a working model of the molecules

Application form

Max 300 characters

French

Example 1

Les fluides non newtoniens

Les propriétées des liquides comme l'eau nous sont bien connus. Mais qu'en est-il de sables mouvants ou de savon liquide? Pas aussi liquide que l'eau, mais pas un solide non plus. Ces propriétées sont appelés non newtoniens, par opposion à l'eau qui est un fluide newtonien. (280 chars)

Example 2

Les fluides non newtoniens

On présente les propriétées étonnantes de ces liquides. A l'opposé de l'eau, ils deviennet plus solides ou liquides si on exerce une force. (144 chars)

Example 3

Liquide ou solide? Vous décidez!

Expérimentez avec les propriétées étonnantes des liquides non newtoniens. A l'opposé de l'eau, ils deviennet plus solides ou liquides si on exerce une force. (162 chars)

German

Example 1

Nichtnewtonsche Fluids

Die Eigenschaften von Flüssigkeiten wie Wasser kennen wir alle, aber was ist Treibsand oder Flüssigseife? Dies sind nicht so flüssig wie Wasser, aber ein Festkörper ist es auch nicht. Dieses anomalviskose Verhalten bezeichnet man als nichtnewtonisch, im Gegensatz zum Wasser das als newtonisches Fluid gilt. (312 chars)

Example 2

Nichtnewtonsche Fluids

Wir präsentieren die überraschenden Eigenschaften dieser Flüssigkeiten. Anders wie Wasser werden sie fester oder flüssiger wenn man Kaft ausübt. (149 chars)

Example 3

Flüssig oder fest? Sie entscheiden!

Erleben die die aussergewöhlichen Eigenschaften der nicht newtonschen Flüssigkeiten. Anders wie Wasser werden sie fester oder flüssiger wenn man Kaft auf sie ausübt. (169 chars)

Pictures

http://www.flickr.com/photos/40925843@N03/5584480784/in/photostream/

http://www.flickr.com/photos/macrj/5393228259/in/photostream/

Planning

meetings

• Bootstrap 2013-02
• Bootstrap 2013-03
• Bootstrap 2013-07
• Bootstrap 2013-09
• ScienceFestival2013Meeting3
• ScienceFestival2013Meeting4

subjects

We have 2 subjects, shear thickening (corn starch) and shear thinning (soap)

Corn Starch

• How to mix?

For the desktop experiments, use your hands!

For the pool, get some big buckets, a drill with an appropriate bit and turn slowly to avoid spraying water, corn starch powder or the mixture.

• Mix ratio?

Experiments show that 1 part water on 2 parts starch give a good mix. When adding to 100ml corn starch 50ml water, the size seems not to increase. Weight ratio: 1kg corn starch is 1.5 L (e.g 1L is 0.666g)

Our pool is arbitrarily chosen to be 2m x 0.4m with a depth of 0.2m This means in total 160L of mixture. That's 106Kg corn starch (plus 54L water)

Add to this the experiments on the first days. We expect to have at max 2 days * 8 workshops * 20 children * 1L mix = 320L Hmm, that's a lot. What about 2 kids do one mix and only 0.5L => 80L. That's another 53kg of corn starch totaling to ~160kg

• Conservation

After some days, especially if it's warm, mold will form and the mix turns bad.

• How to dispose of?

To be confirmed: the mix separates with time into water and a thick mass. The water can go down the drain, the corn starch not! This can be disposed off in plastic bags. If you want to save corn starch, you can dry it and it will turn back into powder.

Kaye effect

Many soaps do not produce the heap which collapses and ejects a filament. But they do nice filaments when the incoming stream moves.

A new phenomenon has been discovered when the soap is drained into a curved bowl. The ejected filament forms little droplets on impact which whiz around on top of the soap film in the bowl until friction wins and they get assimilate into the soapy collective. A slow motion camera comes in handy for this.

Setup: hang a soap bottle above a flat surface or a bowl and let is swing. Cut off the bottom of the bottle to easily fill it up again.

Washing station

(this is not officially announced, as it's a real newtonian fluid, yeah!) Water pump from a fountain cycling water to the top bucket. It drains down in front of loudspeaker. Needs to be dark. An arduino makes soundwave and stobe LED to move the water in waves so it hangs in mid air. Need some foam to catch and filter most of corn starch so the water does not need replaced too often. Need to pay attention that no soap gets put into the fountain. It *will* happen. How to get rid of the foam?