Faezeh Ladani
Ansys Employee

Hi there,

For exporting fields, you may use Fields Calculator to either "Export" the field on your desired grid, or "Write" the field to a file on mesh nodes. Depending on the solution setup options for basis functions, each volumetric mesh element might be represented by different number of mesh nodes, (e.g. 3, 6, 10).

Using Fields Calculator is explained in help document in Post-Processing section. aedtplt is also providing the data on mesh nodes, but it might be easier to work with the file you get out of fields calculator. 

Regarding your objective, it might be more straightforward ways to do it within HFSS and fields calculator. But it should be discussed case by case. If you have access to customer portal, I suggest you submit a support request so that we can work with you on that.