The Normal Current Density node is applicable to exterior boundaries that represent either a source or a sink of current. It provides a condition for specifying the normal current density as an inward or outward current flow:The normal current density is positive when the current flows inward in the domain. Add a contribution as a Harmonic Perturbation by right-clicking the parent node or clicking Harmonic Perturbation on the Physics toolbar. For more information see Harmonic Perturbation — Exclusive and Contributing Nodes.
• For Inward current density enter a value or expression for the Normal current density Jn (SI unit: A/m2). Use a positive value for an inward current flow or a negative value for an outward current flow. The default is 0 A/m2.
• For Current density enter values or expressions for the components of the Current density J0 (SI unit: A/m2). The defaults are 0 A/m2.