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Nonlinear diffusion equation – Weak form PDE
Posted Apr 22, 2015, 4:05 p.m. EDT Chemical Reaction Engineering, Modeling Tools & Definitions Version 5.1 1 Reply
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Dear COMSOL users,
Consider a thin film in the xy plane with an applied magnetic field Ha (A/m) in the z-axis. By increasing Ha, the equation for the time evolution of the local magnetization m (A/m) is :
mt = 2 F^(-1) [ k^-1*F*( div( |grad m|*grad m ) – Hat )]
Where F^(-1) and F are Fourier and inverse Fourier transforms, respectively, and k is the wave vector.
The calculation of the temporal evolution of the local magnetization is based on discrete integration forward in time : mt = (prev(m,1)-m)/timestep, which can be solved by the time discrete solver.
My question is : how can I implement Hat ?
Many thanks in advance for any feedback !
Regards,
Obaid
Consider a thin film in the xy plane with an applied magnetic field Ha (A/m) in the z-axis. By increasing Ha, the equation for the time evolution of the local magnetization m (A/m) is :
mt = 2 F^(-1) [ k^-1*F*( div( |grad m|*grad m ) – Hat )]
Where F^(-1) and F are Fourier and inverse Fourier transforms, respectively, and k is the wave vector.
The calculation of the temporal evolution of the local magnetization is based on discrete integration forward in time : mt = (prev(m,1)-m)/timestep, which can be solved by the time discrete solver.
My question is : how can I implement Hat ?
Many thanks in advance for any feedback !
Regards,
Obaid
1 Reply Last Post Apr 23, 2015, 4:52 p.m. EDT
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Posted:
9 years ago
Do you have please any suggestion how to solve this kind of equation ?.
Thank you,
Obaid