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I need help it this one! Thank you, guys!

Submitted by arturas on

any ideas? :(

 I'd like to help, but this looks suspiciously like it could be an exam question. Is it?  Or is it a homework question?  I guess either way, the following is not an "out-of-bounds" hint.

Think of weighting the momentum balance equation by using the velocity field as a weight function, and integrate over a volume, similar to how one can develop the FE method by using an arbitrary weighting function made of linearly independent basis functions.  Additionally, use the divergence theorem to get the boundary integrals into the solution.

 

Matt Lewis
Los Alamos, New Mexico

Tue, 01/10/2012 - 14:44 Permalink

You probably are not using the definition of kinetic energy...

Forget the right side ... and derive the kinetic energy and use that statement you gave to you.

When you do that, magic happens: balance of mass, incompressibility and Divergence Theorem.

Take care of definitions and all tools that math offer.

I think "GURTIN, M.E. - An Introduction to Continuum Mechanics " a excellent book.

 

Rodrigo

Sat, 02/04/2012 - 20:06 Permalink