Re: [Phys-L] Bernoulli's equation

[John Denker <jsd@av8n.com>]

On 12/15/2014 06:23 PM, Anthony Lapinski wrote:
> I was trying to find some practical/relevant problems involving Bern eqn,
> rather than the typical "plug and chug" problems

Here's something that is probably not directly responsive to
the question, especially in the high-school context, but may
be of some use:

Bernoulli levitation of a disk:
  http://arxiv.org/pdf/physics/0206025.pdf

The advantage is that it really does demonstrate the Bernoulli
principle.  It goes on a rather short list of valid examples:
  -- Airfoil
  -- Pitot-static system
  -- Venturi
  -- Levitating disk

This stands in contrast to the vast majority of the demos that
students see, which claim to demonstrate Bernoulli but in fact
demonstrate nothing of the sort.

One disadvantage of the levitating disk is that you really 
ought to include friction;  otherwise you get implausible 
numbers.  Friction makes the analysis more work and less fun.
I recommend making the roughest possible estimate of the 
friction.

Another disadvantage is that unlike the other things on the
good list above, there are very few practical applications
of Bernoulli levitation.  I've heard of some, but they are
so obscure as to be not worth mentioning.