In recent times, research into scattering of electromagnetic waves by complex objects
has assumed great importance due to its relevance to radar applications, where the
main objective is to identify targeted objects. In designing stealth weapon systems
such as military aircraft, control of their radar cross section is of paramount
importance. Aircraft in combat situations are threatened by enemy missiles. One
countermeasure which is used to reduce this threat is to minimise the radar cross
section. On the other hand, there is a demand for the enhancement of the radar cross
section of civilian spacecraft. Operators of communication satellites often request
a complicated differential radar cross section in order to assist with the tracking
of the satellite. To control the radar cross section, an essential requirement is a
capability for accurate prediction of electromagnetic scattering from complex objects.
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One difficulty which is encountered in the development of suitable numerical solution
schemes is the existence of constraints which are in excess of those needed for a unique
solution. Rather than attempt to include the constraint in the equation set, the novel
approach which is presented here involves the use of the finite element method and the
construction of a specialised element in which the relevant solution variables are
appropriately constrained by the nature of their interpolation functions. For many
years, such an idea was claimed to be impossible. While the idea is not without its
difficulties, its advantages far outweigh its disadvantages. The presenter has
successfully developed such an element for primitive variable solutions to viscous
incompressible flows and wishes to extend the concept to electromagnetic scattering
problems.
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Dr Mack has first degrees in mathematics and aeronautical engineering, plus a Masters
and a Doctorate, both in computational fluid dynamics. He has some thirty years
experience in this latter field. He pioneered the development of the innovative
solenoidal approach for the finite element solution of viscous incompressible flows.
At the time, such a radical idea was claimed in the literature to be impossible.
Much of this early research was undertaken during a six month sabbatical with the
Numerical Analysis Group at the Oxford University Computing Laboratory. Dr Mack has
since received funding from British Aerospace and the United States Department of
Defense to continue this research.