underworldcode
Advection-diffusion convergence issue
With increasing resolution the error is not showing a convergence order:
The errors are concentrated at the diffusive boundary:
unknown (T) degree comparison:
diffusivity (D) value comparison:
To test any updates, the script to check convergence is found here
I had a look at this. I think it is unrealistic to start with a case which has an infinite gradient. I have an example notebook that looks at advection starting from a finite time and looking at the change over time and with advection. I'll upload and you can review.
@bknight1 Take a look at Jupyterbook/Notebooks/Examples-Convection/Ex_AdvectionDiffusion_1dBlock.py.
I'm careful to start from a finite time after the step-function initial condition is applied so that it can be represented reasonably well by the mesh (maybe less so for the simplex example shown). Move it / diffuse it and compare before the analytic solution becomes invalid.
@bknight1 - is this still live with the replacement for the test and the recent debugging ?
Last time I run it the convergence looked a bit better: AdvDiff-HP_setup&results.pdf
Re-running it now to see if the updates make a difference (updated my install to development last night)
These are the results after the update:
AdvDiff_convergence_tol=1e-06_new.pdf
Which appears to be worse...