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September 20, 2010, 10:29 
Time dependent Maxwell equations

#1 
New Member
Liberis
Join Date: Sep 2010
Posts: 9
Rep Power: 6 
Hello guys,
could someone give me a basic guidance on implementing in OpenFoam the system of time dependent Maxwell equations (e.g Microwave modeling,scattering etc ) . The system consists of time dependent electric field and magnetic field components. The mhdFoam solver I think is not able to perform such task. Please help! 

September 21, 2010, 08:18 

#2 
New Member
Liberis
Join Date: Sep 2010
Posts: 9
Rep Power: 6 
Hello again,
trying to solve the coupled system of Maxwell equation, for electric E and magnetic field H, i implemented the following solver, myMicro.C. My computational area is a cube ( 0.1m x 0.1m x 0.1m). On the left side of the cube (say inlet) I set a boundary condition oscillatingFixedValue for E and H in Oy and Oz direction respectively in order to take a wave propagation in Ox. The time step is very low 1e13. After few iterations of the solver the wave stagnates, increases its value and the results are non physical at all... Any ideaaa!!! while (runTime.loop()) { Info<< "Time = " << runTime.timeName() << nl << endl; // #include "readPISOControls.H" // #include "CourantNo.H" tmp<fvVectorMatrix> EEqn ( epsilon0*fvm::ddt(E)==fvc::curl(H) ); // EEqn().relax(); EEqn().solve(); tmp<fvVectorMatrix> HEqn ( mu*fvm::ddt(H)== fvc::curl(E) ); // HEqn().relax(); HEqn().solve(); 

September 23, 2010, 17:12 

#3  
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Corinna
Join Date: Sep 2010
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Quote:
If your approach were successful, you should have been very suspicious about the result. Quote:
Conny 

September 24, 2010, 02:55 

#4 
New Member
Liberis
Join Date: Sep 2010
Posts: 9
Rep Power: 6 
Thanks conny,
I ve already realized that something important is missing from my approach with OpenFoam. Now I try to do my work with the classical FDTD adopting some AMR approaches. But I was wondering if openfoam could solve the Maxwell equation with the suggestion of Shankar, Hall et all for an Finite Volume Ttime domain CFD like solution. 

October 1, 2010, 10:43 

#5  
Senior Member
Mirko Vukovic
Join Date: Mar 2009
Posts: 159
Rep Power: 8 
Quote:
Taking one step & one component as an example, in cartesian coordinates, dE_x/dt will depend on (curl H)_x, all of which are known. Integrating this over a volume, this can be viewed that the (curl H)_x is the source term for E_x in that cell. I did not write the formulas in detail, but I don't see here a matrix solution problem here. Only evaluation of the source term (curl H), and updating the LHS (E). I consider myself an OF and numerical arts novice, but I wonder if the OP used a time step that is too large, or if he set up the initial conditions correctly. Mirko 

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