Discussion Forum

Hi

First of all you must tell us in which direction your field is aligned, 3D magnetic vector potential transforms to magnetic field via a curl and you are in 3D space, so look rather at the cross derivatives, by the way the magnetic field x vector component Bx is equal to the curl(Ax) = Azy-Ayz = d(Az,y)-d(Ay,z) so its easier too use the Axy (y derivative of vector component Ax of A (I find it slightly confusion to have both vector components and derivatives tagged as the same letter, it would have been easier with a 1233 index for vector components and x,y,z for the derivative but OK COMSOl decided once the other way, and now its difficult to change ;)

Then as you have by default quadratic discretization, if you derive once more Bx you will get a rather discontinuous line, you need to increase the discretization to get a continuous result


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Good luck
Ivar

Thank you ivar,

However I think I could find the solution. It is in attached pdf file.

Thank you ivar,

However I think I could find the solution. It is in attached pdf file.

Thanks for your sharing file.

Hi,
How can the gradient of magnetic field generated be used for the force equation of particle tracing. When I am using the terms generated according to the pdf given, the particles are not responding to it. Please help me regarding this.

The u1, u2 and u3 in Pdf are not gradient. they are magnetic field component. You have to put these components in magnetophoretic force section. Chenge the magnetic field to user defined and then put these component in the table.

Hi
Thanks for your response. My force is not a Magnetophoretic force, but let me manipulate the equation for my purpose. Let me see the result.
Thanks again.

Hi,
I am trying to simulate atom trajectory, hence the equation of magnetophoretic force is not suitable, as it having gradient of H^2. Any help regarding this is highly appreciable.

Hi all..

I'm experiencing the same zero gradient problem as defined in the title. I tried the pdf attached. It seems it works fine but the results are nosier than 3.5a(i think if i use finer mesh, results will be better). But i couldnt implement the model via livelink Matlab. I'm trying to solve an optimization problem so matlab and comsol interface is important. When i use the code which i saved from comsol "save as menu", i get magnetic field results okay but the values of dependent variables (u,u1,u2) are always zero.

Any suggestions for coordinating matlab and comsol for this magnetic field gradient problem?

Hi, I have tried lots of method for making a particle trajectory in a gradient of magnetic field produced by multi turn coil. But particles are not responding the force. Please help me regarding this.

Hi Mohamad, you can help me how to put these components in magnetophoretic force section when simulation with particle tracing for Fluid Flow?
Thanks