Difference between revisions of "See the MRF development"

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<math>\left [ \frac{d \vec A}{dt} \right ]_I  = \left [ \frac{d \vec A}{dt} \right ]_R  + \vec \Omega \times \vec A</math>
 
<math>\left [ \frac{d \vec A}{dt} \right ]_I  = \left [ \frac{d \vec A}{dt} \right ]_R  + \vec \Omega \times \vec A</math>
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Position vector:
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<math>\left [ \frac{d \vec r}{dt} \right ]_I  = \left [ \frac{d \vec r}{dt} \right ]_R  + \vec \Omega \times \vec r</math>
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<math>\vec u_I = \vec u_R + \vec \Omega \times \vec r</math>
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For the accelration, the velocity vector is:
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<math>\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \vec u_I}{dt} \right ]_R  + \vec \Omega \times \vec u_I</math>
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<math>\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \left [ \vec u_R + \vec\Omega \times \vec r \right ] }{dt} \right ]_R  + \vec \Omega \times \left [ \vec u_R + \vec \Omega \times \vec r \right ]</math>
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<math>\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \vec u_R}{dt} \right ]_R + \frac{d \vec \Omega}{dt} \times \vec r + \vec \Omega \times \underbrace{ \left [ \frac{\vec r}{dt} \right ]_R }_{\vec u_R}  + \vec \Omega \times \vec u_R + \vec \Omega \times \vec \Omega \times \vec r</math>
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<math>\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \vec u_R}{dt} \right ]_R + \frac{d \vec \Omega}{dt} \times \vec r + 2 \vec \Omega \times \vec u_R + \vec \Omega \times \vec \Omega \times \vec r</math>

Revision as of 20:03, 25 May 2009

Reynolds-Averaged Navier-Stokes formulation in the rotating frame.

Acceleration term expressed for a rotating frame around the z axis ( \vec \Omega).

Notation: I: inertial, R: rotating

General vector:

\left [ \frac{d \vec A}{dt} \right ]_I  = \left [ \frac{d \vec A}{dt} \right ]_R  + \vec \Omega \times \vec A

Position vector:

\left [ \frac{d \vec r}{dt} \right ]_I  = \left [ \frac{d \vec r}{dt} \right ]_R  + \vec \Omega \times \vec r

\vec u_I = \vec u_R + \vec \Omega \times \vec r

For the accelration, the velocity vector is:

\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \vec u_I}{dt} \right ]_R  + \vec \Omega \times \vec u_I

\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \left [ \vec u_R + \vec\Omega \times \vec r \right ] }{dt} \right ]_R  + \vec \Omega \times \left [ \vec u_R + \vec \Omega \times \vec r \right ]

\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \vec u_R}{dt} \right ]_R + \frac{d \vec \Omega}{dt} \times \vec r + \vec \Omega \times \underbrace{ \left [ \frac{\vec r}{dt} \right ]_R }_{\vec u_R}  + \vec \Omega \times \vec u_R + \vec \Omega \times \vec \Omega \times \vec r

\left [ \frac{d \vec u_I}{dt} \right ]_I  = \left [ \frac{d \vec u_R}{dt} \right ]_R + \frac{d \vec \Omega}{dt} \times \vec r + 2 \vec \Omega \times \vec u_R + \vec \Omega \times \vec \Omega \times \vec r