# Some question about saveoldstatus and reloadoldstatus about fluent adapter

**URL:** <https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639>\
**Category:** Official adapters and tutorials\
**Tags:** fluent\
**Created:** [October 31, 2023, 3:44am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639 "2023-10-31T03:44:12Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![ilovenili](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ilovenili/32/1663_2.png) [@ilovenili](https://precice.discourse.group/u/ilovenili)\
**Post date:** [October 31, 2023, 3:44am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/1 "2023-10-31T03:44:12Z")

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hi:  
in fluent\_21\_2\_0 adapter, why so simple about saveoldstatus and reloadoldstatus,as follow:  
if (precicec\_isActionRequired(precicec\_actionWriteIterationCheckpoint())){  
udf\_convergence = 1;  
precicec\_markActionFulfilled(precicec\_actionWriteIterationCheckpoint());  
}  
if (precicec\_isActionRequired(precicec\_actionReadIterationCheckpoint())){  
udf\_convergence = 0;  
precicec\_markActionFulfilled(precicec\_actionReadIterationCheckpoint());  
}

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**Author:** ![ilovenili](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ilovenili/32/1663_2.png) [@ilovenili](https://precice.discourse.group/u/ilovenili)\
**Post date:** [November 3, 2023, 5:27am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/2 "2023-11-03T05:27:59Z")

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my question is :  
Why is there no code related to storing the initial state？

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**Author:** ![IshaanDesai](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ishaandesai/32/1048_2.png) [@IshaanDesai](https://precice.discourse.group/u/IshaanDesai)\
**Post date:** [November 6, 2023, 10:49am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/3 "2023-11-06T10:49:02Z")

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Hi @ilovenili

The variable udf\_convergence is like a boolean which the adapter uses state whether convergence has been achieved or not. The variable is set for use in the `.scm` files by calling:

```plaintext
RP_Set_Integer("udf/convergence", udf_convergence);

```

Once the variable is set, it is used in the `init-fsi.scm` and `solve-fsi.scm` files which actually control the coupling workflow.

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<div class="post-metadata">

**Author:** ![ilovenili](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ilovenili/32/1663_2.png) [@ilovenili](https://precice.discourse.group/u/ilovenili)\
**Post date:** [November 8, 2023, 9:05am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/4 "2023-11-08T09:05:46Z")

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thanks.  
Actually, I mean why does openfoam have to write a lot of code to store all kinds of information about the solver, but fluent only uses one parameter?

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**Author:** ![IshaanDesai](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ishaandesai/32/1048_2.png) [@IshaanDesai](https://precice.discourse.group/u/IshaanDesai)\
**Post date:** [November 10, 2023, 1:10pm UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/5 "2023-11-10T13:10:04Z")

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The way adapters are written for OpenFOAM and Fluent are very different. the The OpenFOAM adapter can handle different types of data, whereas the Fluent adapter can only handle data for a FSI (Fluid Structure Interaction) problem. The intention is to use Fluent as a fluid participant in a FSI coupling. This is one of the reasons why the implementations for implicit coupling look very different for the OpenFOAM and Fluent adapters.

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<div class="post-metadata">

**Author:** ![ilovenili](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ilovenili/32/1663_2.png) [@ilovenili](https://precice.discourse.group/u/ilovenili)\
**Post date:** [November 11, 2023, 11:06am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/6 "2023-11-11T11:06:10Z")

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> [@ilovenili](#):
>
> udf\_convergence = 1;

it’s that: when we use “udf\_convergence = 1”,the fluent have save old data automatic?

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<div class="post-metadata">

**Author:** ![IshaanDesai](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/ishaandesai/32/1048_2.png) [@IshaanDesai](https://precice.discourse.group/u/IshaanDesai)\
**Post date:** [November 23, 2023, 9:03am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/7 "2023-11-23T09:03:52Z")

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HI @ilovenili

Yes, Fluent will save the data when you set `udf_convergence = 1`. The adapter is built for specific applications, and I assume you are using it for a FSI simulation, where Fluent is the fluid participant. So the respective variables will be stored and reused if necessary.

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/precice/original/1X/67d2a5fa6f80e597e2267ff17fa8c1673cd11caa.svg) [@system](https://precice.discourse.group/u/system)\
**Post date:** [November 26, 2023, 9:04am UTC](https://precice.discourse.group/t/some-question-about-saveoldstatus-and-reloadoldstatus-about-fluent-adapter/1639/8 "2023-11-26T09:04:00Z")

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Closed on November 26, 2023, 9:04am UTC

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