Gmsh GetDP question

Christophe Geuzaine Christophe.Geuzaine at ulg.ac.be
Sun Mar 11 12:46:42 CET 2001


Guenter Milde wrote:
> 
> The problem is shortly described as follows:
> 
> * incident radiation is absorbed and causes temperature change
> 
> * heat conduction results in a typical temperature distribution in the sensor
> 
> * pyroelectric effect leads to change in spontaneous polarization
> 
> * change in polarisation leads to change of charge on electrodes
> 
>   pyro-current or pyro-voltage is proportional to mean temperature in active
>   volume
> 
> * surface leakage -> only temperature/radiation changes are detected
> 
> -> for measurement of a steady IR-radiation flow: choppering of incident
>    radiation. Phi -> Phi_0 * theta(t) (modulation function)
> 
> -> We are only interested in the non-steady part: -> Fourier decomposition ->
>    Approximation: Phi -> Phi_0 * cos(omega*t)
> 
> With this, time dependence can be eliminated by using complex values for Phi
> and T. (i.e. analysis in the frequency domain for a set frequency dependence)
> This is what ANSYS calls harmonic anlaysis but only offers for
> mechanical and electrical problems, not for temperature field analysis.
> 

Thanks for the info. I think getdp is quite well adapted for this kind
of simulation (at least the temperature part). After a discussion with
my colleage working on piezzoelectric coupling, it appears that it
works, but requires the use of some non documented functions. I'll try
to add these in the future release of the manual, but you can still send
an e-mail to newly ceated the mailing list (getdp at geuz.org): I'll tell
my colleague to read the list from time to time.

My best,

-- 
Christophe Geuzaine

Tel: 32 (0) 4 366 37 10    http://geuz.org
Fax: 32 (0) 4 366 29 10    mailto:Christophe.Geuzaine at ulg.ac.be