Time-varying electromagnetic field energy storage density

Where there is a time varying magnetic flux density in space?

Eq. (4.21) says: Where there is a time-varying magnetic flux density in space, there is also an electric field. In vector-analytical formulation, Eq. (4.18) contains the following statement. The electric field has vortices, or curls, at locations where the magnetic field changes in time.

What is a time varying magnetic field?

2 1. Time-Varying Electromagnetic Fields where D is the displacement vector, p is the charge density, E is the electric field, B is the magnetic-flux density or magnetic induction, H is the magnetic field, and J is the current density (current per unit cross-sectional area).

What is the energy density of a magnetic field?

H as the 2 energy density, that is, energy per unit volume stored locally in the magnetic field. current changes the magnetization is volume integral of ∫ H ′ dB ′ . However, this energy is not all recovered when the B returns to its initial value because the path of integration is different.

How can the energy stored in the magnetic field be expressed?

In this section, we describe in which way the energy stored in the magnetic field can be expressed by the magnetic field variables. In an inductor with windings close together, the magnetic field is concentrated in the core of the inductor (see Fig. 4.3).

Can time-averaged stored energy density be predicted?

Volume 128, article number 125, ( 2022 ) There exist several nonequivalent expressions of time-averaged stored energy density (TASED) for electromagnetic waves. Correspondingly, different value, even different sign, of TASED may be predicted theoretically.

How to address energy storage and dissipation of electromagnetic waves?

In addition, to properly address the stored energy of electromagnetic wave in the cavity or resonator, the existing expressions of TASED should be used with care. Our work may be helpful to further address energy storage and dissipation of electromagnetic fields and waves arising in various media and/or various applications.