Hi Emanuele, I think this equation is tractable in FiPy with a few tricks. Substituting a single variable for the first derivative in time will give you two coupled equations. I'm assuming the terms in brackets are fourth order terms (can you clarify that). You can also split out the second order derivative of phi into another equation resulting in three equations that can be coupled. The main equation will need a diffusion term with an anisotropic coefficient. The coefficient will have a diagonal of 0 and phi on the off diagonal. So to be clear here are the three things you need to do
- Substitute out the second order time derivative - Substitute out \nabla^2 \phi - Use an anisotropic diffusion coefficient in the main equation These examples are the best examples to get started. - https://www.ctcms.nist.gov/fipy/examples/diffusion/generated/examples.diffusion.coupled.html - https://www.ctcms.nist.gov/fipy/examples/diffusion/generated/examples.diffusion.nthOrder.input4thOrder1D.html - https://www.ctcms.nist.gov/fipy/examples/diffusion/generated/examples.diffusion.anisotropy.html - https://www.ctcms.nist.gov/fipy/examples/phase/generated/examples.phase.anisotropy.html - https://www.ctcms.nist.gov/fipy/examples/phase/generated/examples.phase.polyxtalCoupled.html - https://www.ctcms.nist.gov/fipy/examples/cahnHilliard/generated/examples.cahnHilliard.mesh2DCoupled.html I hope that helps. On Tue, Oct 19, 2021 at 10:47 AM Emanuele Di Palma <[email protected]> wrote: > > Daer all, > I'd like to solve with FiPy the PDE equation reported in the attached file; > I went through the manual and the examples without to find any solution. > Please, let me know if it's possible and eventually addressing toward some > useful example. > > Thanks for your attention. > > Best regards > Emanuele Di Palma > > -- > To unsubscribe from this group, send email to [email protected] > > View this message at https://list.nist.gov/fipy > --- > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. -- Daniel Wheeler -- To unsubscribe from this group, send email to [email protected] View this message at https://list.nist.gov/fipy --- To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
