fenics team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Apr 26, 2007 at 10:32:38AM +0200, Johan Hoffman wrote:
> > On Wed, Apr 25, 2007 at 08:27:40PM +0200, Johan Hoffman wrote:
> >
> >> Yes, boosting interest is good, but why can't the two be combined? I
> >> would prefer a single project dolfin-modules containing a collection of
> >> DOLFIN solvers, including your solvers and others.
> >> >
> >> > /Anders
> >> >
> >>
> >> I do not understand. What other solvers are you referring to?
> >> I talk about to constitute our new project is the Navier-Stokes/Euler
> >> solvers (compressible + incompressible, the ALE-FSI solver, and the
> >> elasticity solver. In the list at
> >> www.fenics.org/wiki/DOLFIN_solver_modules, I can only see Stokes,
> >> Poisson,
> >> heat eqn. and convection-diffusion, apart from these. Are these the
> >> solvers you refer to? I consider these solvers rather being simple
> >> demos,
> >> to either stay in the Dolfin-kernel for demo/test, or to be dropped, not
> >> being part of a solver project for advanced applications.
> >>
> >> If the motive of such a dolfin-module project would only be a showcase
> >> of
> >> a collection of Dolfin solvers, I think we might as well host a webpage
> >> at
> >> the wiki with links to download the solvers from developers together
> >> with
> >> info on what version of Dolfin it works for, and couple this to the
> >> gallery. This would serve the purpose and would minimize maintainment
> >> work. And here our new project would also be present for showcasing
> >> Dolfin.
> >>
> >> The project I suggest is not just a showcase of Dolfin solvers, it is
> >> aimed at developing solvers for automating/generalizing modelling for
> >> advanced applications in different areas. For starters, our NS-solver
> >> for
> >> turbulent flow would fit here as an automated turbulence solver, using
> >> one
> >> simple method (G2 including adaptivity) for "all" turbulent flows
> >> (contrary to common practise of using specific turbulence models for
> >> different flows). We are now working on generalizing this solver to
> >> compressible flow and fluid-structure interaction. Thus there would then
> >> be one solver for turbulent fluid-structure interaction, which would
> >> correspond to automated modeling of FSI.
> >>
> >> So far we have no FEniCS project on advanced solvers or automation of
> >> modeling, so this project would fill that gap, and would not interfere
> >> with any other FEniCS project as far as I can see.
> >
> > True, but why must the set of solvers be limited to NSE with cG(1)?
> 
> It is not, initially it would include incompressible/compressible flow,
> fluid-structure interaction, including visco-elasto-plastic material and
> contact. I am not talking about cG(1), I am talking about G2 which refers
> to Galerkins method together with L2-control of part of the residual (that
> is, it includes about all FEM, FDM, FVM methods) together with a
> posteriori error adaptivity. Which is not that restricted.
> 
> > Examples of other solvers that would be nice to see in a
> > dolfin-modules collection would be the plasticity solver and the
> > other modules we just removed along with the NSE solver. Indeed some
> > of these were very simple, but they don't need to be. The goal has
> > always been that the modules would offer more than the demos. Just
> > having an adaptive and very efficient Poisson solver in such a
> > collection of modules would be very useful.
> 
> They are included, see above.

Is the DOLFIN plasticity solver (that Garth and Kristian wrote)
included? And Poisson?

> >> If the name is disturbing, signaling exclusivity, we can use another
> >> name,
> >> not containing FEniCS or Dolfin. If then someone else want to publish an
> >> advanced solver project at FEniCS that is of course also very welcome.
> >> So
> >> far I have heard nothing about such a project.
> >>
> >> /Johan
> >
> > I don't mind the name, I just think here is a chance to take the
> > DOLFIN modules and make something very good and useful of them, which
> > would be to offer a collection of very efficient, adaptive and
> > polished solvers for a range of equations.
> 
> We have indeed the goal to make this good and useful, and adaptive. And
> sooner or later it will be polished as well.
> 
> I do not see any argument against what we are proposing.
> 
> We could of course publish our solver somewhere else, but that would make
> little sense. I expect this project to be of much benefit for FEniCS, and
> by publishing our development at www.fenics.org we invite to a
> collaborative effort.
> 
> /Johan

I just suggest that you do exactly what you intend + a little more,
which would be to maintain the entire collection of DOLFIN solvers,
not just your own modules.

/Anders