Hello,
I would like to find a steady-state solution of an integro-differential
equation with a spacial variable in the integration limit.
So far it does not work. The minimal working example below gives wrong result.
I understand that M1 and M2 are not updated in sweeps at all. If I set up M1
and M2 initially with the correct solution then the f1 solution is also correct.
if I plug the integration directly to the term
"fp.DiffusionTerm(coeff=fp.numerix.cumsum(f1*mesh.cellVolumes))” the error is:
"IndexError: diffusion coefficent tensor is not an appropriate shape for this
mesh"
How should such equation be arranged?
---
import fipy as fp
mesh = fp.Grid1D(dx=0.002, nx=100)
mesh = mesh + [0.002]
f1 = fp.CellVariable(name = "solution",mesh = mesh,value = 1.,hasOld=True)
x = mesh.x
M1 = fp.numerix.cumsum(f1*mesh.cellVolumes)
M2 = fp.numerix.cumsum(x**2*f1*mesh.cellVolumes)
Conv_pf = [[1.0]] * (M1/x**2)
Diff_pf = (M2/x**3)
eq_steady1 = fp.DiffusionTerm(coeff=Diff_pf) +
fp.PowerLawConvectionTerm(coeff=Conv_pf)
f1.constrain(1,mesh.facesLeft)
for sweep in range(10):
eq_steady1.eq.sweep(var=f1)
f1.updateOld()
Thank you,
Pavel
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