How can I determine Bertotti coefficients when computing iron losses with Flux postprocessor?

According to the Bertotti model, iron losses can be separated into 3 different parts: hysteresis losses, classical eddy current losses and excess losses. Flux will use this formula (for AC supply) for the power density: The Bertotti losses are detailed in the next equation:


which becomes, within the computation frame of Flux:

kf is the coefficient of filling (the stacking factor (0 < kf < 1). This coefficient considers the electrical insulation of the laminations of the magnetic core.

To determine ke and kf, an Excel file which allows fitting the curve of the Bertotti model with the manufacturer data exists and it is provided in C:\Altair\FluxDocExamples_12.3\Tools.