The flow of wet and dry water

Friday we'll finish up our discussion of fluids. So far we've figured out quite a bit:

1. hydraulics (Pascal)
2. energy conservation in fluids without viscosity (Bernoulli)
3. variation of pressure with depth for an ideal fluid
4. work and forces to move fluids

We have a few things to sort out though.

• manometers: how to measure pressure? (simple application of 3 above)
• how do gasses differ? (density variations can't be neglected; 3 + ideal gas law)
• what about purely rotating fluids or smoothly flowing fluids? (energy balance)
• what about buoyancy? why does some stuff float? (3 & 4 for a foreign object in the fluid)
• what about drag forces/viscosity and terminal velocity? (subtle ...)
• what can we say about pressure vessels? (simple generalization of force & pressure)

I've tried for many hours, without success, to find a reasonable explanation of how viscous fluids move and the effects of turbulence without using tons of vector calculus. Fundamentally, I don't think one can do it quantitatively without some serious math, but I think I can give you a qualitative idea of what the issues are and how non-ideal fluids work.

If you are very comfortable with Cal III material, Feynman has a very nice discussion of wet & dry fluids (i.e., with and without drag/viscosity forces): Vol 2 Ch. 40 and Vol 2 Ch. 41. Fair warning, the math is difficult, and beyond what you are responsible for. But, if you're comfortable with the math and want a better idea of how fluids really works, I've not found a better description. Even if the math is too much, his discussions are worth a read - the qualitative descriptions and examples are very lucid.