# \#implicit **URL:** https://precice.discourse.group/tag/implicit/84.md [Latest](https://precice.discourse.group/latest.md) · [Categories](https://precice.discourse.group/categories.md) · [Tags](https://precice.discourse.group/tags.md) --- ## [Where do I need to call requiresWritingCheckpoint()?](https://precice.discourse.group/t/where-do-i-need-to-call-requireswritingcheckpoint/2501)
**Author:** [@wgema](https://precice.discourse.group/u/wgema)\ **Replies:** 3\ **Last updated:** [May 23, 2025, 6:37am UTC](https://precice.discourse.group/t/where-do-i-need-to-call-requireswritingcheckpoint/2501 "2025-05-23T06:37:25Z")
Hello everyone! I am running a coupled FSI Simulation using SU2 and CalculiX, at the end of my simulation I run into the preCICE Error: “—\[precice\] ERROR: The required actions write-iteration-checkpoint are not fulfil… --- ## [Basic understanding of checkpointing with implicit coupling scheme](https://precice.discourse.group/t/basic-understanding-of-checkpointing-with-implicit-coupling-scheme/2391)
**Author:** [@MaxivL](https://precice.discourse.group/u/MaxivL)\ **Replies:** 2\ **Last updated:** [March 31, 2025, 8:37am UTC](https://precice.discourse.group/t/basic-understanding-of-checkpointing-with-implicit-coupling-scheme/2391 "2025-03-31T08:37:12Z")
I‘m currently trying to implement an implicit coupling scheme and want to understand the checkpointing procedure of preCICE to verify my subiteration-output of my fluid und solid solver. I‘m using a parallel implicit sc… --- ## [Implicit Coupling error with Quasi-Newton Acceleration with my adpter. ASSERTION FAILED Expression: \_Q.rows() == \_rows](https://precice.discourse.group/t/implicit-coupling-error-with-quasi-newton-acceleration-with-my-adpter-assertion-failed-expression-q-rows-rows/2067)
**Author:** [@Rodolfo\_Puraca](https://precice.discourse.group/u/Rodolfo_Puraca)\ **Replies:** 1\ **Last updated:** [August 26, 2024, 8:34am UTC](https://precice.discourse.group/t/implicit-coupling-error-with-quasi-newton-acceleration-with-my-adpter-assertion-failed-expression-q-rows-rows/2067 "2024-08-26T08:34:02Z")
Hello, I am developing an adapter using preCICE for the Giraffe solver, an FEM that uses beam elements, similar to MBDyn, for FSI coupling with OpenFOAM. I am conducting various tests to ensure that the adapter works w… --- ## [Convergence issues in multi-coupling scheme](https://precice.discourse.group/t/convergence-issues-in-multi-coupling-scheme/2009)
**Author:** [@dibyendu](https://precice.discourse.group/u/dibyendu)\ **Replies:** 3\ **Last updated:** [July 18, 2024, 2:37pm UTC](https://precice.discourse.group/t/convergence-issues-in-multi-coupling-scheme/2009 "2024-07-18T14:37:48Z")
Dear all, I am attempting to couple multiple regions (three regions) using a multi-coupling scheme. I have based my modifications on the existing “heat-exchange-simplified” solver. An OpenFOAM solver is employed for the… --- ## [A look at compositional coupling and the hotfix v3.1.2](https://precice.discourse.group/t/a-look-at-compositional-coupling-and-the-hotfix-v3-1-2/1992)
**Author:** [@fsimonis](https://precice.discourse.group/u/fsimonis)\ **Replies:** 0\ **Last updated:** [July 2, 2024, 12:15pm UTC](https://precice.discourse.group/t/a-look-at-compositional-coupling-and-the-hotfix-v3-1-2/1992 "2024-07-02T12:15:01Z")
The latest hotfix release 3.1.2 tackles a major problem in a niche use case. In addition to the short release notes, we think it is worth diving deeper into this topic. What is compositional coupling? Imagine three pa… --- ## [What are savestate() and reloadstate() in implicit coupling?](https://precice.discourse.group/t/what-are-savestate-and-reloadstate-in-implicit-coupling/1845)
**Author:** [@fan\_wu](https://precice.discourse.group/u/fan_wu)\ **Replies:** 2\ **Last updated:** [May 6, 2024, 1:20pm UTC](https://precice.discourse.group/t/what-are-savestate-and-reloadstate-in-implicit-coupling/1845 "2024-05-06T13:20:52Z")
Dear community members, I have coupled my immersed boundary method program with calculix. After testing, my Perpendicular flap example has the same results as the official openFoam provided. However, I used a loose coup… --- ## [FSI simulation diverges when using similar density for fluid and solid](https://precice.discourse.group/t/fsi-simulation-diverges-when-using-similar-density-for-fluid-and-solid/1832)
**Author:** [@fan\_wu](https://precice.discourse.group/u/fan_wu)\ **Replies:** 1\ **Last updated:** [May 6, 2024, 11:35am UTC](https://precice.discourse.group/t/fsi-simulation-diverges-when-using-similar-density-for-fluid-and-solid/1832 "2024-05-06T11:35:16Z")
In the official tutorial, in the example of vertical flaps, when I set the density of the solid to be close to the fluid density, divergence occurs. Is it caused by the additional mass effect? Even if I set up an implici… --- ## [How is convergence determined?](https://precice.discourse.group/t/how-is-convergence-determined/1853)
**Author:** [@ilovenili](https://precice.discourse.group/u/ilovenili)\ **Replies:** 1\ **Last updated:** [April 16, 2024, 8:51am UTC](https://precice.discourse.group/t/how-is-convergence-determined/1853 "2024-04-16T08:51:26Z")
hi: Where does precice determine if there is convergence,which function in c++? --- ## [About iterative coupling](https://precice.discourse.group/t/about-iterative-coupling/1604)
**Author:** [@ilovenili](https://precice.discourse.group/u/ilovenili)\ **Replies:** 3\ **Last updated:** [October 13, 2023, 10:15am UTC](https://precice.discourse.group/t/about-iterative-coupling/1604 "2023-10-13T10:15:11Z")
Does precice support iterative coupling? --- ## [What do the API methods in "Step 6 – Implicit coupling" do exactly?](https://precice.discourse.group/t/what-do-the-api-methods-in-step-6-implicit-coupling-do-exactly/1365)
**Author:** [@hongwuw](https://precice.discourse.group/u/hongwuw)\ **Replies:** 3\ **Last updated:** [April 26, 2023, 7:05am UTC](https://precice.discourse.group/t/what-do-the-api-methods-in-step-6-implicit-coupling-do-exactly/1365 "2023-04-26T07:05:23Z")
I have 4 questions regarding: Step 6 – Implicit coupling (Step 6 – Implicit coupling | preCICE - The Coupling Library) (I use the two figures from your website to describe my questions. One figure is the “Fixed time win…