Air Vortex Cannon
When air moves at high speed it creates a spinning motion around an imaginary axis -
We call this an air vortex.
Question:
What variables in the cannon affect the distance of an air vortex?
Hypothesis:
We predict that the shape of the cannon, the size of the hole, the volume of the cannon, and how much strength is used to pull back the membrane, are variables that affect the vortex outcome. We think this because the hole is the last the air reaches in the cannon, so a smaller hole will force the air differently than a bigger hole; the volume of the cannon determines how much air will be pushed out, due to how much is stored; the shape of the cannon, because that effects how the air gets trapped inside; and how much strength that's used to pull back the membrane, determining how much force is out into the vortex blow.
Materials:
1. Plastic cups
2. Punching bag balloon (membrane)
3. Electric tape
4. Drill with different size holes
5. Fog (if you want to see the rings)
6. Paper towel to hang up and threads along the line.
2. Punching bag balloon (membrane)
3. Electric tape
4. Drill with different size holes
5. Fog (if you want to see the rings)
6. Paper towel to hang up and threads along the line.
Procedure:
1. Drill different size holes through bottoms of cups.
2. Cut balloon at bottom so that you are able to stretch the balloon.
3. Stretch balloon over drinking side of cup (you may need someone to hold the cup while this is being done).
4. Put tape around balloon to keep it secure.
5. OPTIONAL- Fill your cannon with mist from humidifier, to see rings, (the actual air vortex itself)
6. Stand at the foot of tape measure.
7. Have your partner go to the 2' mark.
8. Pull back membrane as far as you can and release.
9. Share your results.
2. Cut balloon at bottom so that you are able to stretch the balloon.
3. Stretch balloon over drinking side of cup (you may need someone to hold the cup while this is being done).
4. Put tape around balloon to keep it secure.
5. OPTIONAL- Fill your cannon with mist from humidifier, to see rings, (the actual air vortex itself)
6. Stand at the foot of tape measure.
7. Have your partner go to the 2' mark.
8. Pull back membrane as far as you can and release.
9. Share your results.
The Science behind it
When the membrane is released, it creates an increase of pressure inside the cannon. Since there is a hole for the air to escape, the air is able to leave the cannon, but it is moving fast and that air mixes with the still air outside the cannon. This forms an air vortex.
There is higher air pressure on the outside of the ring and low air pressure on the inside, making the ring spin, keeping it together and allowing it to continue to advance.
Eventually, the ring breaks up because there is too much friction between the fast-moving and still air molecules.
This imbalance of pressure is an example of Bernoulli's Principle and is also the reason why planes fly.
There is higher air pressure on the outside of the ring and low air pressure on the inside, making the ring spin, keeping it together and allowing it to continue to advance.
Eventually, the ring breaks up because there is too much friction between the fast-moving and still air molecules.
This imbalance of pressure is an example of Bernoulli's Principle and is also the reason why planes fly.
Conclusion
Volume of the AVC: The bigger the cannon, the farther the vortex traveled, bigger cannons were easier to use to see the vortex.
Size of the exit hole: A hole cannot be too small or too large. A hole that is too small will make the air vortex fade out faster. A hole that is too big will not offer enough compression.
Shape of the AVC: The shape of the cannon has to have some compression near the exit. This means that the cannon needs to be somewhat cone-shaped.
Force by membrane: The harder you pull the membrane, the farther the vortex travels. However, to see the vortex we needed to just tap the membrane. We also noticed that "medium" sized strength could send the vortex far away.
Size of the exit hole: A hole cannot be too small or too large. A hole that is too small will make the air vortex fade out faster. A hole that is too big will not offer enough compression.
Shape of the AVC: The shape of the cannon has to have some compression near the exit. This means that the cannon needs to be somewhat cone-shaped.
Force by membrane: The harder you pull the membrane, the farther the vortex travels. However, to see the vortex we needed to just tap the membrane. We also noticed that "medium" sized strength could send the vortex far away.
All About... MAE!!! :P
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:):):):):):):):) I am Mae, and my favorite color is... YELLOW!!! I swim in the summer. Like Lily, my favorite subjects are Math and Science. I play violin and piano. I have 7 siblings!! Thank you so much to my AWESOME!!!!!!!!! dad, my AWESOME!!!!!!! mom, and last but not least, Lily's AWESOME!!!!!! dad! |
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The TeamatesWe work together, and make a great team! They both LOVE OREOS!!!!
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