# Boundary Condition: Inductor

## Function:

Defines an inductor for generating or sensing magnetic fields.

## Application:

Point.
The point of application is not geometrically associated to the inductor, but only serves as a reference for applying the condition.

## Description:

Three types of inductors can be defined: Uniform Field, Cylindrical, and Rectangular.
- Uniform Field: The field is applied to the whole domain. It is defined by a direction vector (X, Y, and Z components) with respect to the global coordinate system, by an amplitude (A), and a Phase (P).
- Cylindrical: This defines an inductor with circular cross-section. The direction is defined by a vector X, Y, Z components with respect to the global coordinate system. The inductor is centered on a point with coordinates X, Y, and Z, again with respect to the global coordinate system. Then the inductor's number of turns, outer radius and wall thickness, are entered.
The excitation, when imposed by a non-zero amplitude (A) and phase (P), of the inductor can be done by current or voltage. In both cases, the function is sinusoidal.
- Rectangular: This defines an inductor with rectangular cross-section. A direction vector is defined with components X, Y, Z with respect to the global coordinate system. The center of the inductor is also defined with global coordinates X, Y, and Z. The inductor's number or turns, length, wall thickness, width, depth, and corner radius, are entered.
The excitation, when imposed by a non-zero amplitude (A) and phase (P), of the inductor can be done by current or voltage. In both cases, the function is sinusoidal.

## Remarks:

- The dimensions and coordinates associated to an inductor are in the same units than the rest of the problem (defined in Problem Data).
- Only sinusoidal [A × sin (w × t + P)] forcing functions are allowed. Transient and user-defined forcing functions are not yet implemented.
- When the inductor is excited with a current, A is in amperes. When a voltage is used, A is in volts. The phase P is in degrees.
- When no excitation is defined (or an excitation with A = 0), the coil is not energized. It can be used to sense a magnetic field.
- At this time, only one inductor can be defined per excitation. Mutliple inductors (each one with its excitation) must be applied at different geometry points.
- The amplitude of the excitation (whether current or voltage) must be divided by the factor of symmetry of the model.

## Illustration:

## ATILA Equivalent:

Inductors are placed in the INDUCERS section of ATILA. Refer to the ATILA User's Manual for the complete definition of the parameters.
- When a current excitation is defined, it is placed in the EXCITATIONS section, in the form -N CURRENTn RE IM, where N is the node number where the inductor was applied (this number has no influence on the results), CURRENTn is the current excitation for inductor number n, and RE = A × cos (w × t + P) and IM = A × sin (w × t + P) are the real and imaginary parts of the forcing function.
- When a voltage excitaiton is defined, it is placed in the LOADS section, in the form -N D_FLUXn RE IM, where N is the node number where the inductor was applied (this number has no influence on the results), D_FLUXn is the voltage excitation for inductor number n, and RE = A × cos (w × t + P) and IM = A × sin (w × t + P) are the real and imaginary parts of the forcing function.

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