In the previous section we have seen several examples of nonlinear PDE’s that admit
travelling wave solutions. These solutions are particularly simple in that they reduce the
PDE to an ODE whose solution is required to satisfy only very simple conditions at infinity.
The problem of finding solutions that satisfy the PDE as well as initial and boundary
conditions is much more difficult in general. Very few results of this nature are available but
there are, in fact, some exact solutions for certain problems. We will present some
examples