Is it possible to automatically pause a simulation after the residuals go below a certain value in SimScale? In short, the answer is yes.
For simulations based in OpenFOAM solvers, the definition of the residual threshold is done under the Numerics > Residual controls:
In the image above, the simulation is going to be automatically canceled if all the absolute residuals go below their respective absolute tolerances (in this case, 1e-5).
For example, in the image below, the end time of the simulation was 3000 iterations. However, at iteration 2645, all equations have a residual smaller than 1e-5, causing the simulation to stop:
Furthermore, in the subsonic solver, the stopping criteria is defined under the Simulation Control settings:
Likewise, if the residuals of all equations fall below this threshold, the simulation stops automatically.
It is worth noting that assessing convergence exclusively through residuals is not a good practice. Using result controls to monitor physical quantities of interest, and visually inspecting the simulation results are also important steps to take.