# Fluid Mechanics help

Hey, I'm working on programming a Newtonian mechanics engine (not as part of coursework, btw, for a game that I'm making).

I have some problems, however, as to how to approach fluid mechanics. I know a little bit: buoyant forces, specific gravity, and such. However, I just do not get the more complex (and hence what I need to program) equations and math for viscosity, Newtonian fluids, and such.

Could someone help me understand the basic nature of the following? (I have up to a calculus II knowledge and I know pretty much all of basic, general physics)

1. Sheer stress
2. Fluid viscosity constant --why is it in Pa*s?
3. Can someone give me a good idea of what a gradient is? I understand that mathematically it's a needed idea, and I get the concept of the partial derivative decently well (Though a little help there would be nice, too).
4. What does Newton's partial differential equation for Newtonian fluids mean in words? What does tao signify? (tao = eta*partial derivative(u) of y)

siddharth
Homework Helper
Gold Member
This is usually taught as a separate semester long course, so I think it'd be hard to give a sufficiently deep and broad reply to your questions in a single thread.

If you're learning it for the first time, you'd be much better off reading a book on fluid mechanics from your library. I'd suggest the book on fluid mechanics by Frank M White

Not asking for in-depth stuff, just the very basics of the things asked.

siddharth
Homework Helper
Gold Member
You might find the http://hyperphysics.phy-astr.gsu.edu/hbase/fluid.html" [Broken]webpage on fluid mechanics useful. Still, I strongly suggest that you'd read a fluid mech book, especially for the basics.

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I saw their entry on it, but I still don't get all the variables, what they mean, et cetera.

Wiki has the content, just not the explanation for the content.

And thanks for the diagram, siddharth, it looks like their explanation will help me a bit.

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