Saturday, December 1, 2012

The physics of funneling

By Kathryn Taylor
Being college students we have all seen people funneling beers at parties and we all
have that one friend who seems to be able to do it so much faster than everyone else!
The art of funneling is all in the physics.


Funneling all relates to Bernoulli's principle and the movement of fluids.

Using the Bernoulli's equation:

1/2pv^2 + pgh + P = constant

And the stated assumed values I was able to find that the final speed of the liquid was around 4.89m/s. Using this value in the equation of continuity: dV/dt = Av I found that the time taken for a 12oz (0.000355m^3) beer to pass through the funnel would be 0.14s.

We can also use the reynold's number to find out if the flow of the beer would be
turbulent or laminar. I found an RN of 69693 meaning that the flow is definitely turbulent, which is what makes this so difficult to do quickly!

Along with the turbulence there is also a large decrease in the radius of the hose and the persons throat, increasing the velocity, so making it much harder.

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