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adaptive time stepping

Hi all,
My original time is

#TIME_STEPPING

$PCS_TYPE

OVERLAND_FLOW

$TIME_END

243040

$TIME_START

0

$TIME_STEPS

43200 20

#TIME_STEPPING

$PCS_TYPE

RICHARDS_FLOW

$TIME_END

243040

$TIME_START

0

$TIME_STEPS

43200 20

When I changed the TIME_STEPS to larger value such as 3600, the code rejects the solution. So I want to move to adaptive time stepping.

I found there is an example of TIME_CONTROL SELF_ADAPTIVE in the example: abdul

However, I did not understand the meaning of the parameters. When I use the adaptive time stepping:

#TIME_STEPPING

$PCS_TYPE

OVERLAND_FLOW

$TIME_CONTROL

SELF_ADAPTIVE

4 1.7

10 0.7

MAX_TIME_STEP

100

MINISH

2

It only gave me two results at T=0 and T= 1e308

Do you know how to set up reasonable adaptive parameters for my case?

Thanks,

Xuan

Hi,

We recently updated TIME_CONTROL SELF_ADAPTIVE while keeping compatibility with older versions. You can find updated description of the method in the latest release note:

https://svn.ufz.de/ogs/wiki/ReleaseNotes

If you don't have an account to access the above link yet, please contact to thomas.kalbacher@ufz.de to make it.

Best,
Nori

···

On 01/12/2015 01:08 PM, Xuan Yu wrote:

Hi all,
My original time is
#TIME_STEPPING
$PCS_TYPE
OVERLAND_FLOW
$TIME_END
243040
$TIME_START
0
$TIME_STEPS
43200 20
#TIME_STEPPING
$PCS_TYPE
RICHARDS_FLOW
$TIME_END
243040
$TIME_START
0
$TIME_STEPS
43200 20
When I changed the TIME_STEPS to larger value such as 3600, the code
rejects the solution. So I want to move to adaptive time stepping.
I found there is an example of TIME_CONTROL SELF_ADAPTIVE in the
example: abdul
However, I did not understand the meaning of the parameters. When I use
the adaptive time stepping:

#TIME_STEPPING

  $PCS_TYPE

   OVERLAND_FLOW

  $TIME_CONTROL

    SELF_ADAPTIVE

    4 1.7

    10 0.7

  MAX_TIME_STEP

    100

  MINISH

   2

It only gave me two results at T=0 and T= 1e308

Do you know how to set up reasonable adaptive parameters for my case?

Thanks,

Xuan

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Norihiro Watanabe, Dr.-Ing.
Department of Environmental Informatics (ENVINF)
Wissenschaftler

Helmholtz-Zentrum f√ľr Umweltforschung GmbH - UFZ
Helmholtz Centre for Environmental Research GmbH - UFZ
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Hi

With the svn shutting down last year, is it possible to access documentation on time control elsewhere?

Regards
Swamini

Hey,

You’ll find the keyword documentation here and some infos on adaptive time stepping here.

Example files from benchmarks are e.g.:

1d_ho.tim
h_us_drainage.tim
h_us_line_celia.tim
h_us_line_Forsyth.tim
h_us_line_Halm.tim
h_us_line_Warrick.tim
h_us_quad.tim
h_us_tri_freebc.tim
…

Best,
Timo

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