[Getdp] Integration over time ?

Christophe Geuzaine cag32 at case.edu
Sat May 13 23:23:26 CEST 2006


Thomas Jung wrote:
> Hi,
> 
> sorry for bothering again ...
> 
> In time domain, I have the magnetic vector potential, and a scalar electric 
> potential. I want to compute the time-averaged Lorentz-force 1/T * int (jxB), 
> i.e. integrate the cross-product of current and magnetic induction over one 
> period. For each time step, I can compute the force as 
> 
> Cross[ - sigma[]*(Dt[{a}]+{d v}), {d a} ]
> 
> a=magnetic vector potential, v = electric scalar potential
> 
> If possible, I would not do that as a post processing, as I would need to 
> store every time step then, and are going towards large models.
> 
> Could I perhaps somehow declare a vector field F, and compute and sum up the 
> values inside the time loop? Maybe using "Evaluate" ?
> 
> Was not able to figure that out, thank you very much for any hint !
> 

There's no easy way to integrate in time with the current
post-processing syntax: the best solution is thus probably to save the
time evolution in a file and use another tool to perform the integration
afterwards.


> 
> 
> Thomas Jung
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> 


-- 
Christophe Geuzaine
Assistant Professor, Case Western Reserve University, Mathematics
http://www.case.edu/artsci/math/geuzaine