Finite Difference Numerical Method: Applications in Lightning Electromagnetic Pulse and Heat Diffusion

The finite difference time domain (FDTD) is a technique of the finite difference numerical method and is a simple but powerful and versatile tool that has been widely applied in many scientific and engineering problems. A typical application of the technique is in dealing with electromagnetic (EM) wave interactions with physical structures. This technique has been used to solve governing equations of various systems through obtaining numerical approximations to the time-dependent differential equations for computer simulations. This paper demonstrates the accuracy and versatility of the application of FDTD method by applying it to examine the effect of lightning electromagnetic pulse (LEMP) on a transmission line using a cross-linked polyethylene (XLPE) insulated power cable, as well as to analyze heat diffusion in a microchip heat sink made from Aluminium Alloy 6061. The effect of LEMP on a transmission line showed that the higher the values of the line parameters, the larger the voltages that will be induced on the line and that bigger values of finite difference (FD) parameters give a more accurate model subject to a stability criterion. Accurate modelling of induced voltages ensures that appropriate mitigating techniques can be deployed to reduce or eliminate the damaging effect of these on electrical and/or electronic devices/systems. Similarly, proper modeling of a heat sink provides the ability to closely estimate heat diffusion at product design stage such that a design is confirmed as workable before manufacture; thereby saving cost. Keywords—Finite Difference Method, Finite Difference Time Domain, Engineering Applications, Lightning Electromagnetic Pulse, Heat Diffusion.