chtMultiRegionSimpleFoam - frozenFlow mode results in large errors
Running chtMultiRegionSimpleFoam on a converged flow by activating the frozenFlow switch to calculate the heat transport results in fairly large deviations in the final temperatures as opposed to running the case in the "normal" (fully coupled) mode.
Attached is a 2D case to illustrate the problem. It is a simple case of water flowing at high velocity through a narrow channel above a copper plate which is heated from below.
To reproduce the problem, please do the following steps:
(1) Run the case as it is. The case runs in fully coupled mode for 2000 iterations.
(2) Run the case for the first 1000 iterations by turning off the (h|e) solvers in the ./system/copper/fvSolution and ./system/water/fvSolution subdirectories, i.e, please activate the 'maxIter 0' statement.
(3) Now please turn on the frozenFlow keyword in the PIMPLE subdict and run for another 1000 iterations. In this case, deactivate the 'maxIter 0' statement in the respective fvSolution dicts.
We can see that the Temp. results obtained at the end of 2000 iterations in both cases are very different.
Environment Information
- OpenFOAM Version: v2106
- Operating System: Windows 10 (MinGW)
- Hardware Info: PC (HP Z240)