The Coanda Effect

What You'll Need: 

One Candle
One rectangle such as a small box We used a square glass canister and a bar of soap.
One cylinder such as a can  We used an oatmeal box and a vase.

Put a candle behind a box and try and blow it out.
First we used a rectangular glass canister.
The flame flickered but no one could blow it out.

Repeat the experiment, but this time use a round can. I only caught it before he actually blew it out, but he did blow it out pretty easily.

The boys decided to try a thinner container to see if the results were different.

We had a hard time finding something that was thin and rectangular. We finally found a bar of laundry soap. It was so short, I was afraid that it wouldn't work, but it did. They were unable to blow it out.
Then we used a tall cylindrical vase. It blew out just like we thought it would.

So what is happening in this experiment?
It is called "The Coanda Effect" because in the 1930’s a man named Henri Marie Coanda discovered that a fluid has a tendency to follow a curved surface. He later used this in the design of an airplane that would utilize this “Coanda effect” to its greatest potential.

sources: 

Popular Posts