[aspect-devel] Hanging nodes problem

[Timo Heister]

Lev,

maybe not a solution, but could you try "Use locally conservative
discretization" = true ?

On Fri, May 19, 2017 at 3:27 PM, Lev Karatun <lev.karatun at gmail.com> wrote:
> Hi John,
>
> so I looked at the model for which I had the strainrate strategy enabled
> alongside with composition. It looks like high strainrate is in the cells
> that are already at max refinement level, so they don't get refined. The
> error indicator of the neighboring cells is low. I attached the screenshots
> to illustrate it.
> Another thing I noticed is that there is no anomaly at the last timestep
> that converged successfully. Every time I had this problem, the same pattern
> occured:
>
> timesteps ... - ***0  -- velocity anomaly
> ***mesh refinement occurs***
> timestep ***1 -- no velocity anomaly, successful convergence
> timestep ***2 -- non-convergence
> (hope it's not too confusing)
>
> Best regards,
> Lev Karatun.
>
> 2017-05-19 11:22 GMT-04:00 Lev Karatun <lev.karatun at gmail.com>:
>>
>> Hi Anne,
>>
>> yes, I updated Aspect 4 days ago, and DealII about 2 weeks ago.
>>
>> John, strainrate-based refinement is what also came to my mind when I
>> first faced the problem, and I tried it about a month ago. It also didn't
>> converge, but I don't remember why, and failing to figure it out from
>> looking at the vtu's. I guess I'll just try it again.
>>
>> Best regards,
>> Lev Karatun.
>>
>> 2017-05-19 7:42 GMT-04:00 Glerum, A.C. (Anne) <A.C.Glerum at uu.nl>:
>>>
>>> Hi all,
>>>
>>> Not sure if it is related, but this does remind me of the velocity
>>> anomalies of the chunk geometry when the manifold was removed in the
>>> interior of the domain after AMR (see #1361). But I don’t know how the box
>>> geometry interacts with the manifold, if at all. Did you recently update the
>>> dev versions of dealii or aspect Lev?
>>>
>>> Cheers,
>>> Anne
>>>
>>> On 18 May 2017, at 21:40, Lev Karatun <lev.karatun at gmail.com> wrote:
>>>
>>> Hi Cedric,
>>>
>>> I'm using free slip for the bottom, free surface at the top, prescribed
>>> in/outflow for the sides, and periodic boundary for front/back. I attached
>>> the screenshots.
>>>
>>>
>>> Best regards,
>>> Lev Karatun.
>>>
>>> 2017-05-18 15:04 GMT-04:00 cedric thieulot <c.thieulot at uu.nl>:
>>>>
>>>> Could you please show the viscosity (in log scale), the density and the
>>>> temperature fields ?
>>>> What kind of boundary conditions are you using ?
>>>>
>>>> Cedric.
>>>>
>>>>
>>>> > On 18 May 2017, at 20:24, Lev Karatun <lev.karatun at gmail.com> wrote:
>>>> >
>>>> > Hi all,
>>>> >
>>>> > Lately, several of my simulations crashed with a non-convergence
>>>> > error, and in almost every case there was a velocity anomaly somewhere on
>>>> > the boundary between different refinement levels (see attached screenshot).
>>>> > If I turn off AMR, the problem goes away. I'm using an Iterated Stokes
>>>> > solver, the tolerance is currently 1e-6. I tried lowering the CFL number to
>>>> > 0.1, but it didn't help. I was wondering if anyone had similar problems in
>>>> > the past, and what would be the common approach to deal with them?
>>>> >
>>>> > Thanks in advance!
>>>> >
>>>> > Best regards,
>>>> > Lev Karatun.
>>>> >
>>>> > <mantle_vel_anomaly.png>_______________________________________________
>>>> > Aspect-devel mailing list
>>>> > Aspect-devel at geodynamics.org
>>>> > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.geodynamics.org_cgi-2Dbin_mailman_listinfo_aspect-2Ddevel&d=DwIFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=c08Btfq4m9QEScXN3ZQwLZzzWQE7S8CYq1IYuzKV_Zk&m=2RH_2jlHxn0mPwyErQSqHLr_zTT7TKoulQn2UnrQwig&s=hx-FKONRWbFQ-yCFeaYIf82fpg0lijR0i1k2SbZ0x0c&e= 
>>>>
>>>> _______________________________________________
>>>> Aspect-devel mailing list
>>>> Aspect-devel at geodynamics.org
>>>> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.geodynamics.org_cgi-2Dbin_mailman_listinfo_aspect-2Ddevel&d=DwIFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=c08Btfq4m9QEScXN3ZQwLZzzWQE7S8CYq1IYuzKV_Zk&m=2RH_2jlHxn0mPwyErQSqHLr_zTT7TKoulQn2UnrQwig&s=hx-FKONRWbFQ-yCFeaYIf82fpg0lijR0i1k2SbZ0x0c&e= 
>>>
>>>
>>>
>>> <hanging_node_density.png><hanging_node_T.png><hanging_node_visc.png>_______________________________________________
>>> Aspect-devel mailing list
>>> Aspect-devel at geodynamics.org
>>> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.geodynamics.org_cgi-2Dbin_mailman_listinfo_aspect-2Ddevel&d=DwIFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=c08Btfq4m9QEScXN3ZQwLZzzWQE7S8CYq1IYuzKV_Zk&m=2RH_2jlHxn0mPwyErQSqHLr_zTT7TKoulQn2UnrQwig&s=hx-FKONRWbFQ-yCFeaYIf82fpg0lijR0i1k2SbZ0x0c&e= 
>>>
>>>
>>>
>>> _______________________________________________
>>> Aspect-devel mailing list
>>> Aspect-devel at geodynamics.org
>>> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.geodynamics.org_cgi-2Dbin_mailman_listinfo_aspect-2Ddevel&d=DwIFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=c08Btfq4m9QEScXN3ZQwLZzzWQE7S8CYq1IYuzKV_Zk&m=2RH_2jlHxn0mPwyErQSqHLr_zTT7TKoulQn2UnrQwig&s=hx-FKONRWbFQ-yCFeaYIf82fpg0lijR0i1k2SbZ0x0c&e= 
>>
>>
>
>
> _______________________________________________
> Aspect-devel mailing list
> Aspect-devel at geodynamics.org
> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.geodynamics.org_cgi-2Dbin_mailman_listinfo_aspect-2Ddevel&d=DwIFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=c08Btfq4m9QEScXN3ZQwLZzzWQE7S8CYq1IYuzKV_Zk&m=2RH_2jlHxn0mPwyErQSqHLr_zTT7TKoulQn2UnrQwig&s=hx-FKONRWbFQ-yCFeaYIf82fpg0lijR0i1k2SbZ0x0c&e= 



-- 
Timo Heister
http://www.math.clemson.edu/~heister/