Electromagnetic Modelling of a Lightning Rod

mario_viva.JPGMario Birkic graduated from the University of Split, Croatia and successfully passed his MPhil viva at WIT with his thesis entitled ‘Electromagnetic Modelling of a Lightning Rod’.  The external examiner was Prof Francesco Lattarulo from Politecnico di Bari, Italy and the internal examiner was Prof Carlos Brebbia.

The objective of the research was to study the behaviour of a lightning rod model as a vertically posed monopole antenna representing effective protection for sensitive air traffic control ground-based systems.

The lightning rod representing the simple lightning protection system (LPS) was
assumed to have been mounted on a perfectly conducting ground and a charge free
radiation region.  Thus, in accordance to the image theory the monopole end-driven by the current source was replaced by the twice-longer dipole contrary to the standard wire antenna being normally excited by the voltage generator (transmitting mode,antenna mode), or by the plane wave (receiving mode scattering mode).

The key parameter in the analysis of the lightning rod represented by an equivalent straight wire antenna is the induced current distribution along the wire. The mathematical formulation in the frequency domain of such an antenna current distribution is governed by thin wire antenna theory and the Pocklington’s integro-differential equation.

The lightning induced current along the rod is obtained by solving the homogeneous  Pocklington equation via the Galerkin- Bubnov scheme of the indirect Boundary Element Method BEM.

The thesis has also provided a summary for the theoretical background for natural  Lightning phenomenon and its related international standards.

The efficiency of any lightning protection system (LPS) is normally presented by the  Corresponding protection zone. Thus, the systematic lightning protection design approach defines the measures considering protecting the structures and their electronic systems in order to reduce the risk due to lightning.

Both examiners recommended that Mario be awarded the degree of Master of Philosophy.

Grateful acknowledgement is given to the Foreign and Commonwealth Office for their support.