Hi,
I am trying to simulate the pressure heads in an infiltration basin for a variable flux but I keep getting the same error that says "Numerical solution has stopped because it has not converged in 10 consecutive time steps". I am unable to figure out where I have gone wrong. Could you help fix the problem? Some information specific to the project has been attached here.
Numerical solution not converging
Numerical solution not converging
 Attachments

 time output info.JPG (35.97 KiB) Viewed 234 times

 initial condition.JPG (71.19 KiB) Viewed 234 times

 error.JPG (103.01 KiB) Viewed 234 times

 domain property.JPG (41.88 KiB) Viewed 234 times

 boundary condition.JPG (57.86 KiB) Viewed 234 times
Re: Numerical solution not converging
Please read “Rules about spatial and temporal discretization (FAQ 8: http://www.pcprogress.com/Documents/No ... zation.pdf) and do not do things, which we clearly say that should not be done, such as changing Iteration Criteria. Otherwise I cannot comment on this project since I do not know what your hydraulic properties are, what you boundary fluxes are, etc. J.
Re: Numerical solution not converging
Hi again,
I have read the instructions for temporal and spatial discretization and have tried to follow them. But the solution still doesn't converge. Please find the file for my model attached here. I would really appreciate it if you could help me out!
Thanks,
Saheli
I have read the instructions for temporal and spatial discretization and have tried to follow them. But the solution still doesn't converge. Please find the file for my model attached here. I would really appreciate it if you could help me out!
Thanks,
Saheli
 Attachments

 steady state model.zip
 (249.87 KiB) Downloaded 17 times
Re: Numerical solution not converging
First of all, I do not think that you read those instructions on temporal and spatial discretization since your project clearly does not follow the recommendations.
Anyway, even if it did the program would not be able to run since the problem is not physically realistic. How can you expect that you can enforce a boundary flux that is more than ten times larger than the saturated hydraulic conductivity of the surface layer and hundred times larger than the saturated hydraulic conductivity of the underlying layer? Similarly, since there is no outflow allowed at the bottom and is allowed only on the sides, you should be able to calculate (using simple back of the envelope calculations) what kind of gradient you would need to divert this flux to sides for given hydraulic conductivity. Again, clearly not realistic.
You cannot define an unrealistic problem and expect that HYDRUS will be able to calculate it.
J.
Anyway, even if it did the program would not be able to run since the problem is not physically realistic. How can you expect that you can enforce a boundary flux that is more than ten times larger than the saturated hydraulic conductivity of the surface layer and hundred times larger than the saturated hydraulic conductivity of the underlying layer? Similarly, since there is no outflow allowed at the bottom and is allowed only on the sides, you should be able to calculate (using simple back of the envelope calculations) what kind of gradient you would need to divert this flux to sides for given hydraulic conductivity. Again, clearly not realistic.
You cannot define an unrealistic problem and expect that HYDRUS will be able to calculate it.
J.