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please help me about how to input equations difinited by self
Posted Oct 20, 2010, 9:39 a.m. EDT 1 Reply
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I used the cylindrical coordinate and non-dimensional analysis for the diffusion model, so, the variables, coefficients of the equations are changed, how can I input these new equations. The version of COMSOL I used is 3.5
I appreciate any help!
I appreciate any help!
1 Reply Last Post Oct 20, 2010, 11:09 a.m. EDT
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Posted:
1 decade ago
If you have an axisymmetric model, when you first open the Comsol, on the Model Navigator window you can select "Axial symmetry (2D)" as the space dimension. So that you will have two axes: r (radial) and z (height). Note that there is no 'phi' (angular) axis, since the model is already axisymmetric.
For the dimensionless analysis, you just need to non-dimensionalize your equation by setting
"A = r / rm" and "B = z / zm"
where
r and z are the default radial and height directions, respectively
A and B are the new non-dimensionalized radial and height directions, respectively
rm and zm are the maximum radius and height of your model, respectively.
You need to write (A*rm) instead of 'r' and (B*zm) instead of 'z' in your equation. By organizing your equation, you can obtain the coefficients.
I hope this helps.
Regards,
Özen
For the dimensionless analysis, you just need to non-dimensionalize your equation by setting
"A = r / rm" and "B = z / zm"
where
r and z are the default radial and height directions, respectively
A and B are the new non-dimensionalized radial and height directions, respectively
rm and zm are the maximum radius and height of your model, respectively.
You need to write (A*rm) instead of 'r' and (B*zm) instead of 'z' in your equation. By organizing your equation, you can obtain the coefficients.
I hope this helps.
Regards,
Özen