Wind Tunnel

 

The Challenge:  Familiarize yourself with the wind tunnel and take measurements of drag.

 

The Tools: Our wind tunnel and several geometric shapes.

 

The Tricks of the Trade:

Always warn anyone on the exhaust end of the wind tunnel before you start, because they are going to get blown around.  They will want to make sure all their papers are held down, etcŠ  You, as wind tunnel operator, are responsible to help clean up if your wind creates a disaster.  This is part of your democratic citizenship grade.

 

Directions:

Turn the power on to the wind tunnel and to the hand held controller.

Notice the panel on the top of the wind tunnel has two handles and can be removed.  This is how you will change the shapes inside.

 

Your task: To graph the amount of drag for each object tested versus the wind speed.

 

Using the handheld, test the drag for each number on the handheld.  If you want to be more accurate, you can do half numbers as well, but it is not required.

Select a geometric object and place it on the mount in the wind tunnel.  Take readings using the hand held controller.  Create a chart.  Repeat this for as many objects as time allows.

 

Data tables:

Geometric Shape

Selection on handheld

Drag (g)

For example: sphere

5.5

17

 

 

 

 

 

Calculations:

Graph your results .  (Handheld number on the x-axis, drag on the y-axis).

There should be a separate line for each object tested, but they may all go on the same graph.

 

Questions:

To be answered on a separate piece of paper as an individual for homework.  Please use paragraph structure, complete sentences and observe the conventions of writing.  This may be hand written or word-processed.

 

  1. Did you notice anything about the calibration of the hand held?  Does the amount of wind speed increase in equal increments between each pair of numbers?

 

  1. Based on your results, can you make some generalizations of which objects are most aerodynamic?  How do your graphs support this data?

 

  1. Think of real life objects with shapes similar to the ones you tested.  What are they?  Based on your studies, are those objects designed to be aerodynamic, do you think?  Why or why not? 

 

  1. What are some possible sources of error in this experiment?  What could you do to reduce error if you did this again?