When I studied the fluid dynamic , I saw a quite hard equation (typed in attached file) ,

I don't know how to prove it , maybe there's a somehow relationship between this eq with Gauss's Divergence Theorem ...

Can anyone help me ?

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When I studied the fluid dynamic , I saw a quite hard equation (typed in attached file) ,

I don't know how to prove it , maybe there's a somehow relationship between this eq with Gauss's Divergence Theorem ...

Can anyone help me ?

Your equation is a relation between vectors, but you can prove it by considering each vector component separately and applying the divergence theorem.

Pythagorean
Gold Member
Iirc, you can get at it from conservation of mass:

dm=o
d(pV) =0
(product rule)
etc...

Iirc, you can get at it from conservation of mass:

dm=o
d(pV) =0
(product rule)
etc...

Well,I cannot fully understand what the term "etc" mean , could you be more explicit , or can you just type the solution to this annoying question ?

Thanks again if I get any reply~