95797 - ELETTRODINAMICA QUASI STAZIONARIA E NON STAZIONARIA M

Course Unit Page

  • Teacher Gabriele Neretti

  • Learning modules Gabriele Neretti (Modulo 1)
    Leonardo Sandrolini (Modulo 2)

  • Credits 6

  • SSD ING-IND/31

  • Language Italian

  • Campus of Bologna

  • Degree Programme Second cycle degree programme (LM) in Electrical Energy Engineering (cod. 9066)

Academic Year 2021/2022

Learning outcomes

The course summarizes first the basic concepts of electromagnetism, both in vacuum and in presence of solid matters. Then, a more detailed analysis of non-stationary and quasi-stationary electrodynamics is given, passing through topics such as the skin effect, the free and guided propagation of electromagnetic waves, methods and techniques for the electromagnetic shielding, the calculation electromagnetic forces. A particular emphasis is given to the various electric discharge regimes in direct and alternating current, with reference to specific applications such as lightning strikes, switches and discharges in dielectrics.

Course contents

Module 1

Elements of electromagnetism: vectors of the electromagnetic field, Maxwell's laws, properties of materials.

Electromagnetic forces: forces acting on charged particles,  magnetic and electrostatic forces. Electromagnetic forces  acting on conductive media.

Electric discharges: fundamental properties of electric discharges, thermodynamic equilibrium of plasmas and different discharge regimes

Electric discharge applications: Industrial applications of thermal and non-thermal discharges. High and low pressure plasma processes.

 

Module 2

Nonstationary electrodynamics: Nonhomogeneous wave equations and retarded potentials.

Quasi-stationary electrodynamics: Quasi-stationary approximation. Skin effect.

Waves in an unbounded medium: Uniform plane waves (TEM) in a lossless medium. Uniform plane waves in a lossy medium. Uniform plane waves in a conductor and in a lossy dielectric. Dispersive materials. Analogy between transmission lines and uniform plane waves. Normal incidence of uniform plane waves to a surface.

Electromagnetic shielding: Shielding effectiveness. Methods for the calculation of shielding effectiveness. Shielding of uniform plane waves. Study of an electrically short structure with the diffusion equation of magnetic vector potential and application to multilayered shielding. Shields with apertures. Transfer impedance of enclosures, cables, connectors, junctions. Techniques for the measurement of the shielding effectiveness. Shielding materials.

Basic antennas: Electromagnetic field radiated by elemental dipoles. Electric and magnetic dipoles. Near- and far-field approximation. Near-field impedance. High and low field impedance.

Rectangular waveguides: Solution of the wave equation in a rectangular waveguide filled with a lossless dielectric. Transverse magnetic (TM) and transverse electric (TE) modes. Wave propagation in a guide.


Readings/Bibliography

- J. D. Jackson 'Classical Electrodynamics', Wiley

- J. R. Roth 'Industrial Plasma Engineering', Vol 1 e 2, Institute of Physics Publishing Bristol and Philadelphia

-Fawwaz Ulaby, U. Ravaioli, "Fundamentals of Applied Electromagnetics”, 8th ed., 2020, Pearson.

- D. Cheng, “Field and Wave Electromagnetics”, 2nd ed., 2013, Pearson.

Teaching methods


Laboratory and numerical demos will help students to better understand the material covered in the lessons.

Assessment methods


Oral exam.

Teaching tools


Handouts of slides are available to students on Virtuale Unibo

Office hours

See the website of Gabriele Neretti

See the website of Leonardo Sandrolini