dB/dt in flux 3D transient solver?

User: "Leon Lin"
Altair Community Member

I would like to know if Flux 3D has the functionality to differentiate with respect to time. I want to calculate dB/dt.

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    Hello Leon,

    Thanks for writing.

    It is possible to calculate the derivative of a curve within Flux, you can find more information here:

    https://help.altair.com/flux/Flux/Help/english/UserGuide/English/topics/Courbe2DDerivee.htm

    Best regards,

    Letizia

    User: "Leon Lin"
    Altair Community Member
    OP

    Hi Letizia,

    Thanks for your reply.
    I not only want to plot the 2D curve.

    My goal is to calculate the time-domain ferrite core loss using the iGSE method. This requires integrating a function based on dB/dt, which is derived from the time-domain B(t) data.

    Best regards,
    Leon Lin

    Hello Leon,

    Unfortunately is not possible within Flux: you should export the local quantities versus time and then use an external script to use the iGSE method and compute the derivative.

    Alternatively, iron losses can be calculated using the "automatic" modified Bertotti method available in Flux.

    Best regards,

    Letizia

    User: "Leon Lin"
    Altair Community Member
    OP

    Where can I find the "automatic" modified Bertotti method in flux?

    User: "Ovando_RBB"
    Altair Community Member

    Hi there,

    you can use a current source to feed your model. After the solution converges you will be able to compute the voltage drop at the terminals of the winding that wraps around the ferrite core; that voltage will have intrinsic the overall magnetic action of all the finite elements that are present in the volume of the ferrite core. You can get the plot of that voltage and use it in an external code to estimate the dB/dt.

    Do not forget to subtract the losses from the copper winding before you start doing the logarithmic regression.