[aspect-devel] ASPECT question

[Timo Heister]

(sending to the mailing list)

> I had a quick question about ASPECT.  I’m working on recreating the 2008 Zhong spherical shell benchmarks which involve temperature dependent viscosity jumps up to the order of 1e7.  I notice in the simple material model there is an upper and lower bound on viscosity temperature dependence of 1e2 and 1e-2.  Is there a particular reason for this limit?

This was introduced by Rene way back. I guess it makes sense to limit
in in some way to make the model solvable.

> If the limit is in the code then the solver fails to converge for large thermal viscosity exponents after a few hundred steps, but if I remove these bounds it appears to work fine.

What is your viscosity range in that case? I haven't tested 'very
large' viscosity contrasts yet. There might be stuff that needs
changing in ASPECT to make it work. One thing you can try is using a
constant viscosity per cell for example.

-- 
Timo Heister
http://www.math.clemson.edu/~heister/