Thermal Powered Flower

Thermal Powered Flower

Have you ever seen hot air rise? In this project, explore the physics behind thermal air currents (hot air rising) by harnessing them to power your own spinning flower! Note that this project uses fire and paper, and should only be attempted with adult supervision. Happy spinning!

Check out this video tutorial to see all the steps in action!

9 - 16
Est. Time:
<30 mins

How we did it:

Materials List

  1. straw
  2. clay
  3. colored paper
  4. washer or screw eye
  5. scissors
  6. candle (4)
  7. tape
  8. ruler
  9. lighter
  1. Gather the materials for your thermal-powered flower!

  2. Print out the template (here), and cut a flower and leaf out of your colored paper.

  3. Twist each of the flower petals so that they create a fan shape.

  4. Trim your straw to 3 inches long, and your skewer to 4 inches from the pointed end, using your scissors.

  5. Wrap the clay around your straw so that it stands up vertically. Make sure that there is no clay inside the straw.

  6. Use a piece of tape to secure the eye screw to the top of the straw. This will help reduce the friction between the skewer and the straw when it rotates.

  7. Tape your leaf on to hide the screw eye or washer. Make sure that the leaf won't get in the way of the rotating flower, and also won't rest in the flame.

  8. Use a small piece of clay to attach the center of your flower, to the flat end of the skewer. Slip the skewer inside the straw so the pointed end rests on the table.

  9. Place the four small candles around the base of the straw and light them. Your flower should begin to spin! If it doesn't quite get going on your first try, don't despair, it can take a few adjustments. Try adjusting the screw eye to make sure the skewer isn't touching the straw, or try adjusting the angle at which your petals are folded. You'll also want to make sure that the point of the skewer is rotating on a hard, flat surface, and that your flower is well-balanced on the skewer.

    What's happening?
    As the flames from each candle heat the air up around them, the air expands and becomes less dense than the surrounding, cooler air. This causes the heated air to rise upwards, creating a gentle, warm breeze that causes your flower to rotate just like a pinwheel spins in the wind!