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4 questions
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What does divergence of scalar times vector vector field physically mean?
We know that:
$\nabla \cdot (f \vec{A}) = f \nabla \cdot \vec{A} + \vec{A}\cdot(\nabla f)$
Now divergence of any vector field can be understood in terms of whether the concerning flux is outgoing ($\...
- 15
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3
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Velocity gradient in a liquid
When we consider the motion of fluid in terms of many thin layers sliding over each other , we say that layer at a top of a layer forces it to move forward while layer below a layer forces it to move ...
- 892
2
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Time derivative with respect to an observer moving with velocity $\mathbf{v}$
I am taking a class in fluid mechanics right now and my book has this statement with no explanation:
What is the time derivate seen by an observer moving with a velocity $\mathbf{v}$ of a scalar ...
- 707
3
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3
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Physical Meaning of Divergence of Convective Velocity Term
When taking the divergence of the convective velocity term, I get the following:
\begin{align}
\nabla\cdot\left[\mathbf u\cdot\nabla\mathbf u\right]&=\frac{\partial}{\partial x_i}\left[u_j\frac{\...
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