Hi Drew,
The velocity vector is the velocity magnitude multiplied by the
normal. The normal is the gradient over the gradient magnitude so,
\vec{v} = \frac{\nabla \phi}{\nabla \phi \cdot \nabla \phi}
\frac{\partial \phi}{\partial t}
In Fipy you can get the gradient and gradient magnitude with the
operations ".grad" and ".grad.mag" on cell variables. See, for
example,
https://www.ctcms.nist.gov/fipy/examples/phase/generated/examples.phase.impingement.mesh40x1.html,
where a .grad.mag is used.
Cheers,
Daniel
On Tue, Apr 3, 2018 at 4:55 PM, Drew Davidson <davidson...@gmail.com> wrote:
> Hello,
>
> I was just looking at:
>
> Boettinger, W. J., J. A. Warren, C. Beckermann, and A. Karma. “Phase-Field
> Simulation of Solidification.” Annual Review of Materials Research 32, no. 1
> (August 1, 2002): 163–94.
> https://doi.org/10.1146/annurev.matsci.32.101901.155803.
>
> and maybe Equation 27 is the way to compute interface velocity in
> examples.phase.anisotropy:
>
> v = -\frac{1}{\| \nabla \phi \|}\frac{\partial \phi}{\partial t}
>
> Then it remains to express the right hand side of that equation in the FiPy
> language. It does look like this only gives the velocity magnitude rather
> than the velocity vector.
>
>
> On Tue, Apr 3, 2018 at 12:27 PM, Drew Davidson <davidson...@gmail.com>
> wrote:
>>
>> Hello,
>>
>> In FiPy, how would one calculate the interface velocity at a given time
>> step in examples.phase.anisotropy?
>>
>> At this time, I was mostly interested in the max and min of the magnitude
>> of the interface velocity.
>>
>> Thanks
>
>
>
> _______________________________________________
> fipy mailing list
> fipy@nist.gov
> http://www.ctcms.nist.gov/fipy
> [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
>
--
Daniel Wheeler
_______________________________________________
fipy mailing list
fipy@nist.gov
http://www.ctcms.nist.gov/fipy
[ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
