[Getdp] ?Integration of Results over Surface?

Christophe Geuzaine geuzaine at acm.caltech.edu
Wed Jun 18 09:57:20 CEST 2003


Cezary Sydlo wrote:
> Hello,
> 
> i use the mstrip.pro example to calculate the displacement current by:
> Galerkin { [ epsr[] * Dof{d v} , {d v} ] ; In DomainCC_Ele ; Jacobian
> Vol ; Integration GradGrad ; }
> 
> Then i calculate:
> Name d ;  Value { Local { [ -eps0*epsr[] * {d v} ] ; In DomainCC_Ele ;
> Jacobian Vol ;
> 
> This is from the example file
> 
> QUESTION:
> 
> 1) I want to calculate the capacity by C=QdA ... How can i integrate the
> displacement current over a defined surface. I want to calculate the
> capacity contributions of single elements of a comples 3D structure ...

I guess you could define something like

{ Name C ;
  Value { Integral { [ quantity ]; In surf; Jacobian surfjac;

                                   Integration integ; } }
}

in your PostProcessing, and use

Print[ C[surf], OnGlobal ];

in your PostOperation.

> 
> 2) gmsh is nice, but is there any other possibility to define
> structures? Some converter software maybe?
> 

Sure, you can use whatever CAD+mesh generator combination you like.
You'll just have to transform the final mesh into the .msh format
described in chapter 8 of GetDP's reference manual. This should be
pretty easy, as the info contained in the .msh files is really basic (a
list of nodes and a list of elements).

If you write a converter for some well-known mesh format, post it to
this list. It will probably be useful to other users, too.

Cheers,

Christophe

-- 
Christophe A. Geuzaine
Applied and Computational Mathematics, Caltech
geuzaine at acm.caltech.edu - http://geuz.org