Fluid Race

1
Fluid Race

• Fill long and short drain-pipe cups marked W to
  the same level with water while holding your
  finger over the drain holes. Predict which one
  will empty the fastest then race to see if your
  prediction is correct. Using the second set of
  cups marked S run the race using soap. Please
  dont put soap in the water cups.
• Which cup empties the fastest?
• Why?

2
Heat Pump

• Hold the heat source at the bottom right hand
  corner of the tube and place a drop of dye into
  the tube through the top inlet port. Watch the
  fluid motion. Now switch the location of the
  heat source to the bottom left corner
• Explain how heat causes the fluid to move.

3
The Big Chill

• Place both pipes in the ice water. Do they cool
  down at the same rate? When youre done, take
  both pipes out of the ice bath and see which one
  heats up the fastest by placing them in hot
  water.
• Explain why one metal pipe cools and heats much
  faster than the other.

4
Live Wire

• Bend the wire out of shape (but please do not
  knot the wire). Repeat with the other wire
  provided. Place the wires in hot water.
  Carefully remove and observe what happens.
• Explain the behavior of live wire.

5
Two Balloon Problem

• Inflate one small balloon until it is roughly
  round in shape and attach it on one end of the
  tube (with the valve in the off position). To
  get the balloon on without loosing all the air,
  try twisting the end before attaching it. Repeat
  with one large balloon. Predict which way will
  the air move when the valve is opened. Open the
  valve and see if you are correct.
• Which way does the air flow?
• Why?

6
Entropy Rules

• Examine the silly putty under different
  stresses. Is silly putty a solid or a liquid?
• Predict what will happen when you heat the rubber
  band suspended with the weight on it. Does the
  band expand or contract? Why?
• - Explain the odd behavior of the silly
• putty and rubber bands

7
Under Pressure

• Place a tiny sample of cotton in the into the
  hole in the top of the metal platform, making
  sure some fibers are exposed above the platform.
  Position the piston over the sample with the rod
  extended. Rapidly push the plunger down.
• What happens to the cotton?
• Why?

8
Moonshine

• Apply heat to the glass bulb and observe what
  happens to the mixture of chemicals in the bulb.
  Take samples of the vapor product exiting from
  the top of the still.
• Explain what is happening in this device.
• Why it is happening?

9
Chromatography

• Observe what happens when a mixture of chemicals
  is placed in the column.
• Explain what is happening in this device.
• Why it is happening?

10
Maxwells Demon

• Observe what happens when compressed air is fed
  to the Hilsch tube.
• Explain what is happening in this device.
• Why it is happening?

Note Maxwells Demon is an imaginary genie Who
can separate molecules by their energy
levels Without doing any apparent work.
11
Flaming Marshmallows

• Compare the combustion of marshmallows (which are
  primarily made of sugar), sugar cubes, and sugar
  cubes dipped in ashes.
• Combustion rapid reaction of material
  containing primarily Carbon and Hydrogen atoms
  with oxygen
• Explain why marshmallows will burn (i.e. produce
  a flame) but sugar cubes (w/out ashes) wont.
• Explain why the cube burns when ashes are present?

12
Balderdash true explanations Read the bolded
sentence as the true definition while playing
Balderdash. Then reveal and elaborate on the
true explanation after all definitions have been
voted on. Repeat for each experiment. Fluid
Race Fluid in the cup with the longer pipe
undergoes a greater potential energy change than
fluid exiting from the cup with the shorter pipe.
The potential energy of the fluid is ultimately
converted to kinetic energy (velocity of the
fluid exiting the pipe), therefore fluid exiting
the cup with the longer pipe has a higher
velocity (and drains faster) than the fluid
exiting the shorter pipe. Heat Pump Heating a
fluid causes it to expand (decreasing its
density). It becomes lighter than adjacent
fluid and rises. Colder fluid sinks to replace
the rising warm fluid and a circulation pattern
is set up. The Big Chill The pipe that heats
and cools rapidly is a specially manufactured
device designed to conduct heat at a much faster
rate than conventional copper. It is called a
heat pipe and consists of a outer copper shell
whose inner surfaces are covered with a capillary
wicking material. The innermost portion of the
tube contains liquid water. Vaporization and
condensation of the water leads to rapid heat
transfer in the tube. SEE ATTACHED sheets for
more details. The Two Balloon Problem The air
pressure in the smaller balloon is actually
greater than the pressure in the larger balloon
because the elastic tension in the smaller
balloon (similar to surface tension) is greater
than that in the large balloon. Tension is
proportional to 1/r. The smaller balloon will
shrink until the air pressure in each balloon is
equal. This only works for balloons that are
still relatively elasticI.e. not expanded to
their fullest.
13
Balderdash true explanations Entropy Rules
Polymers have unique properties because they are
made of very long chain molecules. Part A- Silly
putty (dimethylsiloxane) behaves like a solid
(bounces) when the applies stress is of short
duration because the polymer chains do not have
sufficient time to move past each other and
dissipate energy via intramolecular motion
(flow). Silly putty behaves like a fluid, (i.e.
it flows) when the applied stress is of longer
duration (the action of gravity on the putty will
cause it to melt into a puddle if left
otherwise undisturbed). SEE ATTACHED sheet for
more details. Part B- A rubber band contracts
upon heating. When a rubber band is stretched,
its entropy is decreased. Heating the rubber
band increases the entropy (restoring force) and
the polymer chains will tend to return to their
preferred state (coiled). Part C- In the bouncy
ball (polybutadiene), side chains in the polymer
are firmly crosslinked (rigid) and the polymer
behaves elastically (potential energy is
recovered... the ball bounces). In the
non-bouncy ball (polyisobutylene), side chains in
the polymer are not firmly linked and the energy
of impact is dissipated through internal motion
of the polymer molecules. Flaming Marshmallows
It takes more energy to break the crystalline
sugar cube bonds than the non-crystalline
marshmallow bonds (plus marshmallows contain many
ingredients in addition to sugar. The ashes act
as a catalyst to lower the activation energy for
the combustion of cube sugarthe ash-covered
sugar burns at lower temperatures than regular
sugar cubes. Live Wire The live wire is made
from a memory metal. Memory metals are alloys
(Nickel Titanium) which can be trained to take
on a predetermined shape in response to a thermal
stimulus. The shape memory effect is created by
a phase change within the solid state resulting
in the rearrangement of the position of atoms
within the metallic lattice. Heating the metal
provides energy that atoms use to arrange
themselves into a more ordered latticethey slip
back into the phase that they were formed in.
SEE ATTACHED sheets for more details.
14
Balderdash true explanations Moonshine All
chemicals boil at different temperatures. A
mixture of chemicals can be separated into nearly
pure single species by heating the mixture and
preferentially vaporizing the specie with the
lowest boiling point. The nearly pure vapor
product can be condensed and collected. Under
Pressure Work is done on the gas by the piston
resulting in an increase in the internal energy
(temperature) of the gas. The gas heats up
enough to ignite the cotton. Adiabatic
compression results in an increase in the
internal energy of the air.
Maxwells Demon The demon is an imaginary genie
who separates molecules by their energy levels
(fast Moving molecules on the right side and slow
moving molecules on the left side) without doing
any apparent work. Compressed air is fed
tangentially into the Hilsch tube and spirals
down the tube forming a vortex. Angular momemtum
is conserved (slower-moving cooler molecules
gather toward the center to the vortex and faster
ones collect around the outside). An orifice (or
baffle) serves to separate the inner flowing
cooler molecules from the outer flowing hotter
Molecules. Additionally, Momentum is transferred
from high velocity gas (at the outside edge of
the boundary layer) to low velocity gas (at wall)
resulting in the accumulation of low-energy
molecules in the center of the whirling mass and
of high-energy molecules around the outside
Temperatures of 100 F on the hot side and 70 F
on the cool side are possible. Design variables
That affect the temperatures attainable are hot
side outlet area, inlet air pressure, and the
relative size of the orifice compared to the pipe
diameter and spiral size.
15
Engineering 2000 EII Rm 324 Chemical Engineering
BALDERDASH
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Engineering 2000 EII rm 325 Chemical Engineering
of Coffee
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Engineering 2000 EII 204 Chemical
Engineering YESS Program
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Engineering 2000 EII rm 324 Chemical
Engineering YESS Program