  Spiral waves in excitable media possess both wave-like and particle-like
properties. When resonantly forced (forced at the spiral rotation frequency)
spiral cores travel along straight trajectories, but may reflect from medium
boundaries. Here, numerical simulations are used to study reflections from two
types of boundaries. The first is a no-flux boundary which waves cannot cross,
while the second is a step change in the medium excitability which waves do
cross. Both small-core and large-core spirals are investigated. The predominant
feature in all cases is that the reflected angle varies very little with
incident angle for large ranges of incident angles. Comparisons are made to the
theory of Biktashev and Holden. Large-core spirals exhibit other phenomena such
as binding to boundaries. The dynamics of multiple reflections is briefly
considered.
