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Wind Tunnel by Nathaniel

I love auto racing. One thing I've learned about the sport is that most race cars are tested in wind tunnels, so I made one for my science fair project! Then I put a bunch of my car models in it to see how aerodynamic they were. My question: Which vehicle shape is the most aerodynamic?

What did we do?
I grabbed my friends Michael and Ryan, and we found equipment like acrylic sheets, some brackets, two fans, and a lot of tape. We built a wind tunnel and tested five different vehicle designs, including a stock car, an Indy car, a roadster, a truck, and just for kicks, a BOAT! To track air flow, we attached 25 streamers of tissue paper to the surface of each vehicle. If the streamers stayed flat along the vehicle, that meant there was less drag there. For each vehicle, we counted and recorded the number of "flat" streamers.

What did we find out?
Every vehicle we tested had some areas of turbulence on it, shown by some of the streamers lifting up off the vehicle. The vehicle with the most streamers that stayed flat was the Indy car, with 16 out of 25. Next was the stock car (14), and then the boat (that was kind of surprising) with 13 flat streamers. The roadster had the fewest flat streamers, only 8. It was the least aerodynamic. We wondered whether we could add spoilers to make the roadster more aerodynamic. We decided to try that another day.

What can you do?
• Tape little tissue streamers onto the wings of model airplanes, and hold them in front of a fan that is blowing on medium speed. Count and compare the number of flat streamers on each plane. What happens to the number of flat streamers if you tilt the plane upward or downward into the wind from the fan?

• Set up a model town with building blocks. Use toothpicks or small dowels to make little "streamer trees," and place them around the town. Find a household fan and start blowing wind at the town. Do the streamer trees all blow in one direction, or do the buildings change the direction of the wind in parts of the town?

• Use this technology investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!

 SciLinks More on forces of flight. Go to the DFTV Boards, and tell us about your science investigation.

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