Fluid dynamics
An air bubble rising in a tube of Prell shampoo is reported to demonstrate Rayleigh-Taylor instability.
Vortex formation
A drop of inky water is allowed to form on a medicine dropper 1" above a beaker of water a vortex will apparently form in the water. This drop height is said to be critical. The vortex may rebound if the beaker is less than 4" deep.
Use a small paddle to form vortices in a small dish on the overhead projector. Film the screen.
Non Newtonian fluids
A bed of silica powder (fine sand) acts like a fluid when air is forced through it.
A high molarity corn starch solutions in water is thixotropic (like silly putty and 'chemical slime').
A recent version of silly putty breaks when stressd quickly and flows. If the material were warmed it could possibly be used for viscosity and drag studies.
A ping pong ball in the middle of a beaker of beans will rise when the beaker is shaken. The size of an aluminum ball determines whether it goes up or down in a shaking bowl of beans.
If a super soaker fires ketchup across a room, it apparently blobs on the opposite wall.
Adapted from lists at ...
http://www.wfu.edu/physics/pira/ResourceCD/DCS/FluidsDCS.htm
Based on flow behavior, fluids are normally divided into different groups.
Newtonian fluids - for which viscosity is dependent only on temperature
Examples: Water, milk, sugar solution, mineral oilNon-Newtonian fluids (time independent) - for which viscosity is dependent not only on temperature but also on shear rate. Depending on how viscosity changes with shear rate, the flow behavior is characterized as:
1 Shear thinning, whose viscosity decreases with increased shear rate.
Examples: Paint, shampoo, fruit juice concentrates, molten plastic
2 Shear thickening, for which viscosity increases with increased shear rate
Examples: wet sand and concentrated starch suspensions
3 Plastic, which exhibits a so-called yield value, i.e. a certain shear stress must be applied before flow occurs.
Examples: toothpaste, hand cream, grease
Non-Newtonian fluids (time dependent) - for which viscosity is dependent on temperature, shear rate and time. Depending on how viscosity changes with time the flow behavior is characterized as:
1 Time thinning - viscosity decreases with time.
Examples: yogurt, paint.
2 Time thickening - viscosity increases with time.
Example: gypsum paste, (also known as Plaster of Paris.)
Lists adapted from ...