# Error while coupling Atmospheric Boundarly Solver PALM with an In-house CFD solver **URL:** \ **Category:** Using preCICE\ **Tags:** adapters\ **Created:** [July 24, 2026, 9:06am UTC](https://precice.discourse.group/t/error-while-coupling-atmospheric-boundarly-solver-palm-with-an-in-house-cfd-solver/2991 "2026-07-24T09:06:32Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Manish](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/manish/32/3351_2.png) [@Manish](https://precice.discourse.group/u/Manish)\ **Post date:** [July 24, 2026, 9:06am UTC](https://precice.discourse.group/t/error-while-coupling-atmospheric-boundarly-solver-palm-with-an-in-house-cfd-solver/2991/1 "2026-07-24T09:06:32Z")
[precice-config.xml](https://precice.discourse.group/uploads/short-url/vJnlPk7E2O8V9qqXUIJ0xAxM6EK.xml) (2.1 KB) [FLOWer\_Log.txt](https://precice.discourse.group/uploads/short-url/7fOe6JYvJIdlEHljoW8jxZqr4TK.txt) (1.4 KB) [debug1.log](https://precice.discourse.group/uploads/short-url/bqxIdKRl4unaIZpNuwF5jExJlr1.log) (150.4 KB) [PALM\_log.txt](https://precice.discourse.group/uploads/short-url/2iGd7QE3pB5lMukZRdn7NlEeGbs.txt) (9.2 KB) Dear preCICE team I am trying to couple an incompressible Atmospheric Fluid Solver called PALM, with an In-house FORTRAN based compressible CFD solver for carrying out unsteady simulations. PALM is used to carry out simulations on a bigger domain (D1), whereas the CFD solver is utilized for a smaller domain (D2) embedded within D1. The task of the coupling framework is to inject values obtained from D1 at at the interface boundary planes of the smaller domain D2 that is the inflow, lateral planes and the top planes of D2. The process of developing the required adapters were initiated by testing the respective solvers to exchange variable values using dummy solver. In the second stage, the same adapters are being utilised for coupling PALM and my in-house CFD solver. In the current state of this coupling framework, the two solvers are able to connect, initialise and also start the coupled simulations. In the first stage of this implementation, only one-way coupling is implemented, wherein velocity components will be injected from PALM to the second solver’s interface planes (mentioned above). I have tested this framework using two different grid configurations of D2, called as Fine D2 and Coarse D2. The coupled simulations get started and data exchange begins successfully for both the solvers and both the grid configurations: 1. In the case of Coarse D2, PALM and CFD solver completes the simulations for the entire prescribed time steps (tested till 900 time steps). 2. In the case of Fine D2, PALM runs its complete set of time steps (which seems correct as there are no changes in its overall mesh configuration). On the other hand, CFD solver with the finer Mesh, runs for only limited time steps and just stops without presenting any error. I tried some debugging and noticed that CFD solver stops at the advance(dt) phase. In the meantime simulations in PALM complete and has exchanged data with preCICE buffer using write\_data. When I run the CFD simulations using mpirun, I notice that only one of the processes goes to sleep mode, whereas the other processes are just waiting. ---
**Author:** ![Manish](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/manish/32/3351_2.png) [@Manish](https://precice.discourse.group/u/Manish)\ **Post date:** [July 29, 2026, 8:45am UTC](https://precice.discourse.group/t/error-while-coupling-atmospheric-boundarly-solver-palm-with-an-in-house-cfd-solver/2991/2 "2026-07-29T08:45:11Z")
Dear All This is just an update on my current problem. Once I restarted the system, this problem seemed to have solved and the coupled simulations are now running the entire prescribed time duration. Thus, the problem is solved. ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/precice/original/1X/67d2a5fa6f80e597e2267ff17fa8c1673cd11caa.svg) [@system](https://precice.discourse.group/u/system)\ **Post date:** [August 1, 2026, 8:45am UTC](https://precice.discourse.group/t/error-while-coupling-atmospheric-boundarly-solver-palm-with-an-in-house-cfd-solver/2991/3 "2026-08-01T08:45:39Z")
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