2C40.20 - Streamline Flow - Blow Out a Candle

Code Number:
Demo Title:
Streamline Flow - Blow Out a Candle
Coanda Effect, Streamline Flow Around Objects
Area of Study:
Heat & Fluids
Candle in Holder, Lighter or Matches, and 2 L Soda Bottle.

Place a lit candle about 18 inches from your mouth. A 2 L soda bottle is partially filled with water. This is placed between you and the candle and then you blow directly at the bottle. The candle will be blown out  on the back side of the bottle because the flow of air is directed around the curved sides of the bottle.

  • Martin Gardner, "Three for Bernoulli", Science Tricks, p. 19.
  • Borislaw Bilash II, David Maiullo, "Streaming Toward a Candle", A Demo a Day: A Year of Physics Demonstrations, p. 194.
  • Martin Gardner, "Blowing Out a Candle", Entertaining Science Experiments With Everyday Objects,  p. 104.

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