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recipes:common:navier_stokes

If there ever was a universal formula of everything 1) this is it:

of state

$PV=nRT\,$ or $p-p_0=B\left(\left(\frac{\rho}{\rho_0}\right)^m -1\right)$ 2)

of conservation of momentum

$\rho \left(\frac{\partial u}{\partial t} + u \frac{\partial u}{\partial x} + v \frac{\partial u}{\partial y} + w \frac{\partial u}{\partial z}\right) -\frac{\partial}{\partial z}\left(\mu\left(\frac{\partial u}{\partial z} + \frac{\partial w}{\partial x}\right)\right) - \rho g_x $ $=-\frac{\partial p}{\partial x} + \frac{\partial}{\partial x}\left(2 \mu \frac{\partial u}{\partial x} - \frac{2\mu}{3} \nabla \cdot \mathbf{v}\right) + \frac{\partial}{\partial y}\left(\mu\left(\frac{\partial u}{\partial y} + \frac{\partial v}{\partial x}\right)\right)$

$\rho \left(\frac{\partial v}{\partial t} + u \frac{\partial v}{\partial x} + v \frac{\partial v}{\partial y}+ w \frac{\partial v}{\partial z}\right) - \frac{\partial}{\partial z}\left(\mu\left(\frac{\partial v}{\partial z} + \frac{\partial w}{\partial y}\right)\right) - \rho g_y $ $=-\frac{\partial p}{\partial y} + \frac{\partial}{\partial x}\left(\mu\left(\frac{\partial v}{\partial x} + \frac{\partial u}{\partial y}\right)\right) + \frac{\partial}{\partial y}\left(2 \mu \frac{\partial v}{\partial y} - \frac{2\mu}{3} \nabla \cdot \mathbf{v}\right) $

$\rho \left(\frac{\partial w}{\partial t} + u \frac{\partial w}{\partial x} + v \frac{\partial w}{\partial y}+ w \frac{\partial w}{\partial z}\right) - \frac{\partial}{\partial z}\left(2 \mu \frac{\partial w}{\partial z} - \frac{2\mu}{3} \nabla \cdot \mathbf{v}\right) $ $=-\frac{\partial p}{\partial z} + \frac{\partial}{\partial x}\left(\mu\left(\frac{\partial w}{\partial x} + \frac{\partial u}{\partial z}\right)\right) + \frac{\partial}{\partial y}\left(\mu\left(\frac{\partial w}{\partial y} + \frac{\partial v}{\partial z}\right)\right)+ \rho g_z $

of mass continuity

$\frac{\partial \rho}{\partial t} + \nabla \cdot (\rho \mathbf{v}) = 0$ 3)

of conservation of energy

$ -\rho \frac{D h}{D t}=\frac{D p}{D t} + \nabla \cdot (k \nabla T) + \mu \left(2\left(\left(\frac{\partial u}{\partial x}\right)^2 + \left(\frac{\partial v}{\partial y}\right)^2 + \left(\frac{\partial w}{\partial z}\right)^2\right) \\\\+ \left(\frac{\partial v}{\partial x} + \frac{\partial u}{\partial y}\right)^2 + \left(\frac{\partial w}{\partial y} + \frac{\partial v}{\partial z}\right)^2 + \left(\frac{\partial u}{\partial z} + \frac{\partial w}{\partial x}\right)^2\right) + \lambda (\nabla \cdot \mathbf{v})^2$4)

1)
for a given value of everything, in this case: halfway sane fluids
2)
pick the later for water for example
3)
this is much worse than you can imagine from its simplicity right now
4)
or why your 5x100W surround receiver with 400W input power does in fact not constitute a perpetuum mobile
recipes/common/navier_stokes.txt · Last modified: 2013/06/16 11:16 by low