[dean993]

Hi,
Does anyone know how to exactly transfer magnetic field data to the external magnetic field option in the fluent MHD module. From what I see the external mag. field data format in the fluent mhd is quite strange (see attachment).

Thanks,
Dean

[eduardvinter]

For someone, this topic remains relevant.
Can anyone explain the structure of the file that dean993 attached?
What does "data point" mean in the MHD fluent manual?

[LuckyTran]

You just provide a big giant list in the order given

nX = number of x coordinates
nY = number y coordinates
nZ = number of zcoordinates

X1 thru Xn, listall the x coordinates up to nX in number
Y1 thru Yn, list all the y coordinates up to nY in number
Z1 thru Zn, list all the z coordinates up to nZ in number

nAc freq

BXre means real part of Bfield in X-direction,

BXim means imaginary part of Bfield in Y-direction

[eduardvinter]

This part of the file is clear.

I encountered a misunderstanding of the term "data point" in the manual.

Information from the Appendix C of MHD module manual:

The rest of the data file contains the magnetic field data points. Each line defines the components of
the real and imaginary parts of the magnetic field vector on one data point. The data points are indexed
as:
l=i+nX((j-1)+nY(k-1))
i=1,...,nX, j=1,...,nY; k=1,...,nZ
The data is listed in the ascending order from 1 to n, where n is the total number of data points given
by n= nXnYnZ.

As I understood l is a line number in the array of B.

For instance, I have an alternating magnetic field calculated in ANSYS APDL. I can write APDL macro for extracting magnetic field induction from each element, but I have to extract this magnetic field induction from each data point. What is it?

Thanks

[LuckyTran]

The meaning of external is that it comes from some black box without any meaning. You have fields at x,y,z. Just list them. It doesn't matter to the interpreter whether they come from faces/cells/nodes.