Using Table(B,H) Method for Permeability

The Table (B,H) method provides a stable iterative scheme for setting the magnetic permeability of a material using B - H curves. With this method, you provide a table of discrete ( B , H ) values. Simcenter STAR-CCM+ interpolates the imported values and constructs a continuous B - H curve.

The input table is a two-column table of ( B , H ) values, with the following requirements:
  • The first entry must be (0,0).
  • The values must be monotonically increasing, that is, the values of each ( B , H ) pair must be larger than the values of the previous ( B , H ) pair. If the curve is not monotonic, Simcenter STAR-CCM+ outputs an error message and the simulation stops. A typical monotonic B - H curve looks as follows:

    When the ratio ΔB/ΔH for two consecutive table entries is less than the vacuum permeability μ 0 , Simcenter STAR-CCM+ automatically adjusts the B - H curve so that ΔB/ΔH=μ0 and prints a warning to the Output window.

    A typical ΔB/ΔH curve looks as follows:

The column headings can contain units specification. During import, Simcenter STAR-CCM+ converts the specified units to SI units (see File Format Reference), provided that the specified units are defined under the Tools > Units node (see Defining Units).

For instructions on how to import a B - H table in Simcenter STAR-CCM+, see Defining Permeability Using a B-H Curve.

Simcenter STAR-CCM+ interpolates the imported values and constructs a continuous B - H curve. When B becomes greater than the maximum flux density value that is provided in the table, Simcenter STAR-CCM+ extrapolates the values. Simcenter STAR-CCM+ may correct the last two data points to make them consistent with the extrapolation.

The interpolation and extrapolation methods change depending on the magnetic vector potential model in use:
Interpolation/Extrapolation Finite Element Magnetic Vector Potential model Finite Volume Magnetic Vector Potential model
Interpolation the imported table values are interpolated using a monotonic spline the imported table values are interpolated using a linear-piecewise interpolation method
Extrapolation the B - H curve is smoothly extrapolated by an exponential function with its slope approaching the vacuum permeability the B - H curve is extended at a slope of μ 0 from the last point