# Current orientation of coil conductor regions in Flux 3D

## Introduction

This chapter discusses the current orientation of coil conductor regions (without losses and with losses and both simplified and detailed geometrical descriptions) in Flux 3D. Orienting the current in a coil conductor region is an essential action that must be performed while describing a project and before launching the solution of the electromagnetic simulation.

The following topic is discussed in this documentation:
• How to orient current sense for coils in Flux 3D.

## How to orient the current sense of coil conductor regions in Flux 3D

In Flux 3D, coil conductor regions may be considered "open" or "closed." An open coil conductor region may be assimilated to a bundle of stranded conductors, in which the input and output terminals are represented by different sets of geometrical faces and are said to be External. On the other hand, a "closed" coil conductor region has both terminals represented by a single set of geometrical faces; its input and output terminals are coincident and are said to be Internal. Both situations are depicted in Figure 1.

In either case, orienting the current sense of a 3D coil conductor region consists in selecting the appropriate faces belonging to the volume(s) assigned to the region.

After completing the creation of a coil conductor region and assigning it to one or more volumes in the domain, the orientation of its current sense in Flux 3D may be set in accordance with the following procedure:
• In the Physics menu, select Orient wires of coil conductor regions (completion mode);
• Then choose the Volume coil conductor region to be oriented in the list and inform if the type of its terminals is either External or Internal;
• Flux will then ask the user to select and provide a certain number of geometrical entities:
• If the terminals are External, two distinct sets of faces describing the input and the output terminals are required. For this type of terminal, the current is always oriented from the input terminal to the output terminal as shown in Figure 1(a).
• If the terminals are Internal, a single set of faces describing the coinciding "input - output" terminal and a line describing the current path are required. For this type of coil conductor region, the current is always oriented in the direction of the selected line, as shown in Figure 1(b).
To modify the assignments of faces to the terminals of coil conductor regions in Flux 3D:
• In the Physics menu, select Orient wires of coil conductor regions (modify mode). This action is also available in the context menu displayed by right-clicking on the coil conductor region in the Data Tree or in the Graphic view.