Format and Execute Options

Analysis > Options > Solution Settings > Format and Execute Options

The Format and Execute Options allow the user to set the options which will be taken by Flux solver (in batch) to solve the current solution.

Mesh options

Mesh Relative Epsilon allows to define the limit to consider two nodes as superimposed or not.

The Mesh absolute Epsilon is computed by multiplying the Mesh Relative Epsilon (1e-5 by default) by the diagonal of the bounding box of the solution bodies.

The distance between two nodes is compared to the Mesh absolute Epsilon value: if it is lower then the nodes are considered as superimposed.

Soft non linear B(H) approximation

In Magnetic AC solutions, the quantities as the magnetic field H and magnetic flux density B are sinusoidal time dependent.

But in reality, when soft non linear materials are considered, H and B cannot have both sinusoidal time dependency simultaneously.

To take this consideration into account, an approximation can be done by using one of the following models:

Model Hypothesis Equivalent B(H) curve
Curve not modified - Real B(H)
Sine wave flux density B sinusoid

 This model is based on the following energetic equivalence:

This model is more adapted for the simulation of devices with a voltage supply.
Sine wave magnetic field H sinusoid

 This model is based on the following energetic equivalence:

This model is more adapted for the simulation of devices with a current supply.
Mixed - This model is the linear combination of the two preceding ones:

where α is a weighting coefficient chosen empirically in the interval [0,1]
Average value of Nu over a cycle B sinusoid

 This model relies on an equivalent reluctivity νeq calculated by getting the average of reluctivity over a period of time:

It is much less precise than the others for high values of magnetic flux density, as it does not observe the asymptote of µ0 slope.
The most commonly used models are:
  • Sine wave flux density
  • Sine wave magnetic field
  • Curve not modified
The Automatic mode which is enabled by default works as following:
  • If a voltage source component exists, Sine wave flux density model is used
  • If a current source component exists, Sine wave magnetic field model is used
  • If there is no source or if both sources type exist, Curve not modified is used

Coefficient for circuit connected coils

A coil is defined by two objects:
  • an electrical component of stranded coil conductor type defined in the circuit
  • a coil geometrically defined entity to define the shape of coils
A coil is described in a finite element domain that can be bounded by symmetries and/or periodicities.
  • from an electric point of view, there is only one electrical component
  • from a geometric point of view, there is an "original" coil (the one described in the FE domain) and its "duplicates" by symmetry and/or periodicity

In this situation, the electrical component is a component that comprises several geometric coils.

To compute the magnetic flux through this component (i.e. through the "original" coil and its "duplicates"), Flux evaluates:
  • the coefficient CM, which takes into account the number and types of symmetries and/or periodicities
  • the field Conductors in series or in parallel, which takes into account the configuration type of associated conductors (all in series, all in parallel).

In the Automatic mode which is suitable for most cases, the coefficient CM takes into account the number and types of symmetries and/or periodicities.

But it is possible to define manually the coefficient CM defined either as an integer or a fraction.

An example which needs a manual CM definition is a speed sensor defined with symmetry/periodicity, but the coils must not be duplicated. Then CM is defined by the value 1.

The 3 possible choices are explained in the table below:

Option Description
Automatic coefficient (symmetry and periodicity taken into account) CM is automatically computed with taking active symmetries and active rotation periodicities of the problem into account.
Imposed coefficient (integer)

CM is an integer:

CM = N

N is the number of repetitive patterns described in the finite elements domain

(The finite elements domain corresponds to 1/N fraction of the real device)
Imposed coefficient (fraction)

CM is a quotient of 2 integers:

CM = N1/N2

The finite elements domain corresponds to 1/N1 fraction of the real device.

N1 is the number of repetitive patterns described in the finite elements domain

N2 is the number of repetitive patterns supplied by the electric circuit

Execute Solver Options

The Execute Solver Options define the options used at Flux solver execution:
  • Number of Processors used to parallelize the solving process
  • Memory used by Flux solver. By default, the memory is set to Dynamic memory allocation. It is possible to switch to a user defined memory (static memory) and specify the amount of memory to allocate
  • GUI memory defined statically by a given memory amount
  • Additional_Arguments is an advanced option to add additional arguments information like system memory, PEEC memory and so on. Input should be space separator. Example: -fluxncores 4 -memsizn3_mb 6000 -memsizc3_mb 200

Activate distribution

In Magneto Static and Magnetic AC solutions with a Motion load and constraint, it is possible to distribute the solving steps on several Flux. The distribution allows the user to save computation time.
  • Number of concurrent Flux defines the number of Flux that will be running at the same time during a distributed computation
  • Multithreading cores defines the number of cores used by each secondary Flux