Coil Index¶

Scalar field that labels each cell with the zero-based index of the CoilSpecification it belongs to, in the order you added the specifications to the ExcitationCoilModel. It complements Coil Group: Coil Index tells which coil a cell belongs to, Coil Group tells which body of that coil.

Registered name: "Coil Index".

Per-cell value:

Cell location	Value
Inside the `i`-th `CoilSpecification`	non-negative integer \(i = 0, 1, \dots\)
Outside every coil	NaN

The NaN outside-coil value renders as the configured NaN colour in ParaView, so coil cells stand out visually against the rest of the mesh.

All coil reports (current, voltage, resistance, back-EMF, flux linkage) use the same index as their coil_index argument. So this coefficient lets you confirm which integer addresses which physical winding.

Example: IPM-motor stator¶

Figure 1: Coil Index on the 24-slot stator of the IEEJ IPM benchmark. Three CoilSpecifications — one per phase — are added in the order U, V, W and receive indices 0, 1, 2. All eight conductor bodies of phase U share the same colour, and likewise for V and W. The surrounding air domain is rendered in ParaView's NaN colour (green here).

Combine Coil Index and Coil Group to distinguish every individual sub-coil at a glance. The index identifies the phase. The group identifies the sub-coil within that phase.