Fluid Dynamics

Atoms-01

Atoms

Homeopathy

Make a homeopathic sleeping drug.

Put one drop Coke in first gallon. Mix well ('succuss').

Put one drop in 2nd gallon. Mix well.

Put one drop in third gallon. Mix well. Pour into cup.

3 gallon jugs clean water

3 eye-droppers

Colored liquid (eg: Coke)

Clear plastic cup

Density-01

Density

Density

Weigh the items to show they have the same weight.
Display the items to show they have different volumes.

3 equal weight but different density masses.

0.5 kg Fe, Al and wood

Display (round) spring scale.

Designation

Topic

Name

Description

Materials

Photo

Pressure-01

Static Pressure

Egg Stand

Fill beakers with sand.

Shake to pack the sand.

Place eggs in them pointed end down with half the egg buried.
Place beakers on paper towel on hard floor.
Place wooden plate on beakers so the eggs are under the corner pads.
Stand on the plate very slowly.

Make sure the eggs don't shift.

3 plastic beakers

Blue triangular wooden plate

Sand

4 eggs (raw)

Paper towels, broom, and dustpan

Beaker to break an egg into (prove it's raw).

Pressure-02

Static Pressure

Seat of Nails

Sit on it.

Get volunteer.

Bring out the Starter Seat and ask them to start with just one nail.

Watch reactions!

Seat of Nails

1-Nail Seat of Nails

Pressure-03

Pressure

Equal Height Tubes

Pour liquid into tubes.

All liquid levels are at the same height since all have the same pressure at the base of the tube.

Equal Height Tubes

Dark food coloring

UMd - F1-06

Pressure-04

Pressure

Pascal's Tube

Put in colored water.
Push in the plunger.
Watch water squirt out of all the holes in the end.

Pascal's pressure tube

Dark water to fill it with

Pressure-05

Pressure

Drop Holey Cup

Puncture a Styrofoam cup and the water will drain out.
Puncture it and drop it. Will the water drain out?
If you use the predrilled plastic cup, make sure there are several inches of water in the bucket to soften its landing.

3 Styrofoam cups or predrilled plastic cup

Water

Bucket

Pen to puncture the cup

Density-01

Density

Density

Weigh the items to show they have the same weight.
Display the items to show they have different volumes.

3 equal weight but different density masses.

0.5 kg Fe, Al and wood

Display (round) spring scale.

Buoyancy-01

Buoyancy

Float/Sink

What floats? What sinks?

Water tank

Different materials

Buoyancy-02

Buoyancy

Buoyancy Force

Weigh the masses in the air.
Weigh them in the water.
The difference is the buoyancy force.
Larger objects have a larger difference.

Small aquarium tank with at least 6" of water

Round visible spring scale

Masses of different materials (from demo #2)

Buoyancy-03

Buoyancy

Sink or Float

Ask class whether Al foil sinks or floats.

If they choose sinks, make a boat and float it.

If they choose floats, place a sheet under water and watch it sink.

Note: Crumpled Al foil floats!

Water tank

Aluminum foil

Buoyancy-04

Buoyancy

Finger in Beaker

Put beaker of water on pan balance. Balance it.
Ask: If you add sinker (eg: metal), will the beaker go up, down or stay the same? Do it.
Ask: If you add floater (eg: wood), will the beaker go up, down or stay the same? Do it.
Ask: If put finger in water without touching beaker, will the beaker go up, down or stay the same? Do it.

Pan balance

Beaker of water

Weights to balance

Small sinker and floater weights

Buoyancy-05

Buoyancy

Boat and Rock

Place weight in bottle (the boat) in the water so it floats.
Ask class: What will happen to the water level when the rock is dumped overboard?
Dump the rock overboard.

Small aquarium tank half-filled with water

Tape to mark water level

Cut-out soda bottle (2-liter!!!) with screw-top

1.5kg of 100g or 250g masses

UMd - F2-05

Buoyancy-06

Surface Tension

Paper Clip Float

Place the dish of water on the overhead projector or display it with a video camera.

Bend one paper clip into an L shape and use it to gently lower the second paper clip onto the surface of the water.

Then add a drop of soap to the water to decrease the surface tension and watch the paper clip sink abruptly.

Paper clips (2 minimum)

Soap

Petri dish of H2O

Buoyancy-07

Compression

Squiddy

Place squiddy in cup of water.

Adjust buoyancy by squeezing to let water in until barely bouyant.
Place squiddy in water bottle and cap it.
Squeeze bottle to make squiddy sink.

Squiddy

Cup of water

Sealable soda bottle w/water

Buoyancy-08

Added 3/14

Buoyancy

Battleship in Bathtub

Ask the class whether the large block of wood can float in water weighing much less than the block.

Pour water into the container and and place the block into the container.

Large piece of pressure treated wood

Clear acrylic container approximately the same dimensions as the block of wood

Buoyancy-09

Added 3/14

Capillary Action

Capillary Action

Four glass tubes of different diameter are connected at the base.

The height of the water in each tube is determined by the effects of surface tension.

The water is spiked with food coloring to enhance its visibility.

Capillary Tubes

Water

Food coloring

Portable Elmo camera

UMd - F3-11

Atmospheric Pressure

Vacuum to Table

Connect the vacuum pump to the valve.

Lay on table or connect two of together.
Vacuum out much of the air.
Close the valve.
Ask a student to pull apart the hemispheres or remove from table.

Flat Magdeburg spheres

Vacuum pump

Air Pressure-02

Atmospheric Pressure

Break Ruler w/ Newspaper

Place fibreboard so about 4" sticks over end of table.

Place newspaper over fibreboard. Smooth the paper over the board.

Hit exposed end of board hard!

PRACTICE

1/8"x3/4"x24" fibreboard

Newspaper

Air Pressure-03

Atmospheric Pressure

Magdeburg Spheres

Connect the vacuum pump to the sphere.
Vacuum out much of the air.
Close the valve on the sphere.
Ask a student to pull apart the hemispheres.

Magdeburg spheres

Vacuum pump

Air Pressure-04

Atmospheric Pressure

Soda Can Crush

Put about 1 oz of water in soda can and jam cardboard square under the pull tab to cover the hole.

Ignite propane torch.
Grab can with tongs near the bottom. Tilt can and hold bottom corner over torch to boil the water.
Wait until lots of steam comes out of the can.
Quickly place can upside down into water container.

Crunch!

Empty soda cans

Large container of water

Tongs

Propane torch

Ignitor

Small cardboard square

Air Pressure-05

Atmospheric Pressure

Vacuum Cannon

Cover bottom end of vacuum cannon with Al foil and secure it with the hose clamp.
Drop the ping pong ball down the cannon barrel.
Place the soda can bottom over the top end of the cannon.
Attach the vacuum pump to the vacuum cannon.
Point the cannon away from people (or at a target).
Turn on the vacuum pump.
If the Al foil does not rupture spontaneously, poke it with the screwdriver.

Vacuum cannon

Vacuum pump

Heavy duty Al foil

Ping pong ball

Screw driver

UMd - I3-18

Air Pressure-06

Atmospheric Pressure

Reverse Balloon Inflate 1

Slightly blow up a balloon and tie off.
Place balloon inside hand-held vacuum pump.
Use the pump to remove the air.
The balloon gets bigger.

Reverse balloon inflator

Air Pressure-07

Atmospheric Pressure

Reverse Balloon Inflate 2

Place small balloon in bell jar.
Pump down.

Small balloon

Vacuum pump

Bell jar

Air Pressure-08

Atmospheric Pressure

Cup of Water w/ Cardboard Lid

Fill cup with water.

Place cardboard over top.

Invert over top the bucket.

Air pressure holds the cardboard in place.

Cup of water with even rim

3-4" cardboard square

Bucket

Air Pressure-09

Atmospheric Pressure

Holey Cup w/ Lid

Cover hole.

Fill cup with water.

Place cardboard over top.

Invert over top the bucket.

Air pressure holds the cardboard in place.

Remove finger from over hole and air pressure fails.

Solid clear plastic cup with even rim and 1/4" hole on the side near the base

3-4" cardboard square

Bucket

Air Pressure-10

Atmospheric Pressure

Glug Glug

Pour water from bottle.

It goes glug glug.

Air pressure keeps the water from pouring in a steady stream.

Full water bottle (narrow neck)

Bucket

Air Pressure-11

Air Pressure

Tornado Tube 1

Water does not easily go from top bottle to bottom unless you give it a swirl to start a vortex.

Two soda bottles

Tornado tube coupling

Water

Air Pressure-12

Air Pressure

Tornado Tube 2

Water does not go from top bottle to bottom unless you give it a swirl to start a vortex.

Two water cooler bottles

Tornado tube coupling

Water

Air Pressure

Hero's Fountain

(Small)

Fill one bottle half full of colored water.

Connect the bottles with the coupling.

Turn the bottles over.

Two 2-liter bottles

Fountain coupling

Food coloring

Water

Air Pressure-14

Coming Soon

Air Pressure

Hero's Fountain

(Large)

Air Flow-01

Bernoulli

Alligator Eyeballs

Place two small balls in eyecups.
Blow through mouthpiece constantly to 'levitate' the eyeballs.
Disinfect mouthpiece .

Alligator eyeballs

Air Flow-02

Bernoulli

Funnel and Ping Pong Balls

Attach tube to narrow end of funnel.

Hold funnel upside down.

Hold ball inside inverted funnel.

Blow hard through tube to keep the ball in the funnel.
PRACTICE!

Small funne

Long tube

Ping Pong ball

UMd - F5-05

Air Flow-03

Bernoulli

Straw, Spool, Pin, and Card

Place the straight pin through the center of the index card.
Bend the flexi-straw 90 degrees.

Put the short end through the center of the thread spool (so the end is flush or slightly recessed).
Place the card on the spool so that the pin rests in the straw
A) Card on top of the spool (blowing up): distribute lots of these to students and offer a large sum of money to the first student who can blow the card off the spool by blowing through the straw.
B) Card underneath the spool (blowing down): Blow hard to keep the card from falling. This is a much easier Bernoulli demo than Air Flow-02.

Bendy straw

Thread spool

Straight pin

Index card

UMd - F5-07

Air Flow-04

Bernoulli

Bottle Mouth and Ping Pong Ball

Place the ping pong ball in the bottle top.
Challenge students to blow hard enough to blow the ball out of the bottle top (blowing upwards).
It also works blowing downwards (see Air Flow-02) but you run out of air very quickly because the aperture is too big.

Cut off the top 2in of a plastic drink Bottle

Ping Pong ball

Air Flow-05

Bernoulli

Bernoulli Car

Wind up car.
Place ball on smokestack.

Turn on.

(Ping pong ball will NOT work.)

Bernoulli car

Small Styrofoam ball

UMd - F5-01

Air Flow-06

Bernoulli

Blower and Ball

Turn on blower.
Place ball in airstream.
Release.
Tilt or move blower (slowly).

Air track blower

Hose with contriction or nozzle

Small and/or Medium Styrofoam ball

Ping Pong ball

UMd - F5-06

Air Flow-07

Bernoulli

Blow Over Paper Sheet

Hold one end of a sheet of paper in front of and below your mouth.
Blow over it (or slightly down).
Watch it rise up.

Paper sheet

Air Flow-08

Bernoulli

Blow Between Objects

Bblow between the balls.
They move closer to each other.

Two basketballs suspended by 2 strings

Blower

Air Flow-09

Coming Soon

Bernoulli

Blow Over Airfoils

Blow over flat and airfoil shaped pieces of Al.
Which rises more?

Blower
Hose without nozzle or constriction

Various Al airfoils

Air Flow-10

Bernoulli

Bernoulli Bags

Get two students

Ask them each to inflate a bag.
Show the one how to cheat.

Bernoulli bags (tie off one end on each)

Air Flow-11

Magnus Effect

Curve Balls

Place a ball near one end of the thrower. Throw it like in Jai Alai.

Watch it curve.

Curve ball thrower

Medium Styrofoam balls

Bernoulli

Coanda Effect

Place the leaf blower on the ground and turn on.

Carefully position the ball in the air stream.

Angle the leaf blower and the ball stays.

As the leaf blower is turned off the ball will slowly lower towards the blower.

Small beach ball

Leaf blower

Vortex Rings

Smoke Rings

Fill air cannon with fog-in-a-can. Smack the back of the air cannon.

Air cannon

Fog-in-a-can