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0 votes
1 answer
33 views

Solving for a linear equation from a nondimensionalisation

Whilst doing my homework I came across the following question and got particularly stumped at question c). I do not know how I could possibly derive a precise linear relationship. Any help? When a ...
Geralt's user avatar
  • 1
1 vote
1 answer
487 views

Deriving the Thin-Film Equation from Navier-Stokes Equations

I want to start with the general Navier-Stokes equation in 3-D: $$ \frac{\partial \vec{u}}{\partial t} + (\vec{u}\cdot\nabla)\vec{u}=-\frac{1}{\rho}\nabla p+\frac{\mu}{\rho}\nabla^2\vec{u}+g\sin{\...
Mjoseph's user avatar
  • 1,019
0 votes
0 answers
239 views

Fluid Mechanics. How to nondimensionalize a variable with a power law index.

can anyone help me in nondimensionalizing these equation? I start from the equation in the first line. Using the nondimensional variable from the third line, I get the half-completed equation in the ...
Akimi 's user avatar
0 votes
0 answers
100 views

Problem with Dimensional Analysis - Darcy's velocity

Once, by the Darcy law, the flux of a fluid with viscosity $\mu$ in a porous media with permeability $K$ between the points $a,b$ (with distance $L$) is given by $$Q=-\dfrac{K}{\mu}(p_b-p_a)\dfrac{...
Quiet_waters's user avatar
  • 1,525
0 votes
1 answer
128 views

What are the units of every vector in the codomain of the vector field $\textbf{F}$?

I don't understand how the rate at which a fluid flows along the bottom edge of a rectangular region A in the direction of i is approximately $\textbf{F}(x,y)\dot{i} \Delta x$. In physics, the rate as ...
Cake's user avatar
  • 135
2 votes
1 answer
492 views

Green's Theorem Derivation and Explanation on the dot product with $\mathbf{\vec F}(x,y+\Delta y) \cdot \mathbf{\vec j}\,\Delta x$

Green's Theorem gives that the flux on a vector field $\mathbf{\vec F}$ over a closed curve C is equal to the double integral over the enclosed region of C of the divergence of $\mathbf{\vec F}$ (...
Cake's user avatar
  • 135
0 votes
1 answer
253 views

Normalizing (Non-Dimensionalising) the Young-Laplace equation

I have a simple fluid statics problem of a liquid drop, resting on a stationary flat solid surface with a static gas of constant pressure above. The density in both the gas and liquid are constant. To ...
Mike Pegg's user avatar