Mary Jackson, wind tunnels and energy conservation

What you'll need

• Mary Jackson, wind tunnels and drag slideshow
• Supplies to create 'wind tunnel' (see slideshow):
  • Two 2-litre pop bottles
  • Scissors and tape to join the bottles
  • Hair dryer with cold setting
• Craft supplies for students: 
  • Small paper cups 
  • Pieces of paper
  • Pipe cleaners and pom poms
  • Popsicle sticks 
  • Glue, scissors, and tape

Introduction

Start the activity by having a class discussion about important women who have contributed to STEM throughout history, or do the Women in history: who do you know activity first to learn about some examples.

Mary Jackson and wind tunnels

1. Pull up the Mary Jackson and wind tunnels slideshow. Start at slide 2 and ask students if they remember anything about Mary from the previous activity, or review the information about Mary Jackson on the slide.
   
   
2. At slide 3, tell students about Mary’s work with NASA. This included research with their Supersonic Pressure Tunnel, a wind tunnel capable of blasting models with winds approaching twice the speed of sound. Share that aerodynamics describes the study of air and water on objects like aircraft and cars.
   
   
3. At slide 4, describe how wind tunnels are used to contain a controlled stream of air. Objects are placed in the tunnel and tested to see how they perform with various pressures of wind.
   
   
4. At slide 5 ask students why we would use wind tunnels. 
   • They allow us to study aerodynamics of objects (the way they move) so we can change the design and improve performance. Explain that when an object moves through a fluid like air, how it moves is affected by several factors: 
     1. weight (pulling the object down) 
     2. thrust (pushing the object forward like the wind or engine)
     3. lift (which is an upwards force make the object fly) 
     4. drag (which pulls the object back).
        
        
5. Explain wind tunnels allow engineers and scientists to test effects of wind in a controlled environment and then can change the design to make it more effective. Wind tunnels are used in many situations, including vehicles, buildings and structures, wind turbines and more.
   
   
6. At slide 6, pause the slide show and hold up 2 pieces of letter sized paper and ask students to vote on which piece will hit the ground first. Now at the last minute as you let go of the pieces of paper scrunch up one and release both at the same time. What happened? The scrunched piece of paper will hit the ground first. Why? Both are the same weight and both are affected by gravity. One factor is that the scrunched piece has less surface area and hence less ‘drag’ and the flat paper is shaped to create ‘lift’ making the paper fly.
   
   

Experiment and analyze

1. Share with students they are now going to create some objects out of simple craft supplies and test them in a wind tunnel to see if we can get them to hover in the tunnel, and not just fly out of the tunnel.
   
   
2. Before the class, create one wind tunnel for all students to test their designs. Cut the two 2-litre pop bottles and join them together to form a longer tunnel using clear packaging tape. Slide 7 is a picture of the tunnel we created. Show students your tunnel and hold the hair dryer (cold setting only) vertically under the tunnel to provide the ‘wind force’. Have students put items like pompoms in the bottom of the tunnel and see what happens. Try holding the hair dryer close to the tunnel and then further away. What happened? Student helpers can hold the tunnel as you test various items.
   
   
3. Now provide students with a selection of craft supplies like small paper cups (bathroom size), paper, pipe cleaners, pompoms small popsicle sticks, glue, scissors and tape. Slide 8 shows the sample craft supplies to collect.
   
   
4. Have students design their craft to test in the tunnel. Slide 9 shows the sample designs students can make and test.
   
   
5. Now test your crafts in the tunnel. Try holding the hair dryer closer and further away. Can you get your craft to hover?  Remember to only use the cold or cool setting on the hair dryer.
   
   
6. At slide 10 reflect on what happened to your crafts in the tunnel:  
   • Why did your craft hover or fly out of the tunnel?  Some factors affecting your craft include thrust (the wind from the hair dryer), weight and drag/lift determined by the shape of your craft.
   • What happened when you held the hair dryer closer or further away?
   • Discuss as a class the results and why some designs were more effective at hovering than others.
      

Aerodynamics and energy conservation

1. At slide 11, re-visit the term ‘drag’. Share that when an object (or person) moves through fluids (like air or water) they will encounter resistance called drag forces. The person is using their energy to run but when they pull or drag a parachute behind them, they must work harder to overcome this resistance. If the running force is the same as the drag force they would be running on the spot.
   
   
2. At slide 12, ask students to share what the cyclist is doing to go faster and reduce drag forces. The cyclist is leaning forward making themselves smaller and their helmet is shaped so the wind goes around the helmet. This helps them go faster while conserving energy. They are ‘aerodynamic’.
   
   
3. At slide 13, ask students to choose if A or B is more aerodynamic (designate one side of the room as ‘A’ and one ‘B’ and students can move to one side of the room or the other to answer). At slide 14 reveal the answer. The umbrella is causing drag as wind pulls the person back.
   
   
4. At slide 15, ask students to choose if A or B is more aerodynamic. At slide 16 reveal the answer. The shape of vehicle A makes it more aerodynamic.
   
   
5. At slide 17, ask students to choose if A or B is more aerodynamic. At slide 18 reveal the answer. The open windows cause drag making the car less efficient.  
   
   
6. At slide 19, ask students to share why aerodynamics for our vehicles matter? Students may share that aerodynamic vehicles use less energy. Energy could be diesel, gasoline, natural gas for a combustion engine vehicle or electricity for an electric vehicle. Ask students to consider what features they have seen that makes vehicles less aerodynamic. Roof racks and containers, trailers, uncovered truck beds are examples of what can make vehicles less aerodynamic.
   
   

At slide 20 wrap up the activity by asking students to discuss what other things can be tested in wind tunnels like bicycles, wind turbines, ships, spacecraft, airplanes, submarines, buildings and fans. Wind tunnels can be life size or scaled down physical tunnels or computer simulated.