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third order differential equation
Posted 30.06.2017, 08:17 GMT-4 2 Replies
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Hi All,
It looks like COMSOL can not handle third order differential equation in Coefficient Form to solve Eigenvalue problem.
I would like to implement this equation:
d^3/dx^3
Any help will be appreciated.
Regards
Sanjay Prabhakar
Post-doc Fellow
Physics, Vanderbilt University
It looks like COMSOL can not handle third order differential equation in Coefficient Form to solve Eigenvalue problem.
I would like to implement this equation:
d^3/dx^3
Any help will be appreciated.
Regards
Sanjay Prabhakar
Post-doc Fellow
Physics, Vanderbilt University
2 Replies Last Post 01.07.2017, 17:48 GMT-4
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Posted:
7 years ago
Updated:
7 years ago
Sanjay,
To calculate the higher derivatives, you may define them as a new variable and solve them coupled to the other physics in your model.
To understand how to do this, see the following example by Marc Fernandez Silva:
www.comsol.com/blogs/plotting-spatial-derivatives-magnetic-field/
Hope that they resolve this issue in the newer versions.
Amin,
To calculate the higher derivatives, you may define them as a new variable and solve them coupled to the other physics in your model.
To understand how to do this, see the following example by Marc Fernandez Silva:
www.comsol.com/blogs/plotting-spatial-derivatives-magnetic-field/
Hope that they resolve this issue in the newer versions.
Amin,
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Posted:
7 years ago
Thanks Admin,
I think, I figure it out, how to implement third order derivative as follows:
In coefficient form, there is a term \Delta. (....+\gamma)
\Delta can be \partial_x and \gamma can be uxx (second derivative of u w.r.t. x). This gives "third derivative of u w.r.t. x.
Thanks for sending your paper and I will be reading your paper very carefully.
Thanks
Sanjay
I think, I figure it out, how to implement third order derivative as follows:
In coefficient form, there is a term \Delta. (....+\gamma)
\Delta can be \partial_x and \gamma can be uxx (second derivative of u w.r.t. x). This gives "third derivative of u w.r.t. x.
Thanks for sending your paper and I will be reading your paper very carefully.
Thanks
Sanjay