Talk:Derivation of the Navier–Stokes equations

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[edit] Notation?

Does it change from Q_i to b_i for a source/sink of momentum? —Preceding unsigned comment added by 140.184.21.115 (talk) 13:40, 19 September 2007 (UTC)

Q is used for the generic conservation, b is used in the context of momentum. —Preceding unsigned comment added by Ben pcc (talk • contribs) 23:11, 24 October 2007 (UTC)

[edit] Reynolds Transport Theorem

I'm surprised that, in a derivation of the Navier-Stokes equations, that there is no mention of the Reynolds Transport Theorem.

--71.98.78.28 04:12, 11 June 2007 (UTC)

Good point. -Ben pcc 02:23, 28 June 2007 (UTC)

[edit] Outer Product?

Would the relations for \mathbb{T}_{ij} in the discussion on Newtonian fluids be equivalent to saying \mathbb{T} = \mu (\nabla \otimes \mathbf{u} + (\nabla \otimes \mathbf{u})^T) + (\lambda \nabla \cdot \mathbf{v}) \mathbb{I}, where \mathbb{I} is the identity matrix? --Zemylat 17:57, 25 October 2007 (UTC)

I think so. I just added something that looks a lot like that minus the outer products, I think they're equivalent. I'm not using the outer product notation because my sources (MIT OCW "Surface tension module" and my fluid mechanics teacher) don't either. — Ben pcc 02:30, 3 November 2007 (UTC)

Scratch that. Using the outer product is more mathematically sound and there is zero ambiguity. Thank you! — Ben pcc 17:30, 4 November 2007 (UTC)