  The approach presented in the second installment of this series is extended
to multidimensional systems of conservation laws that are approximated via a
Discontinuous Galerkin method on unstructured (triangular) grids. Special
attention is paid to predicting the entropy dissipation from boundaries. The
resulting schemes are free of tunable viscosity parameters and tested on the
Euler equations. The trinity of testcases is the spreading of thermal energy
from a point source, transsonic and supersonic flows around airfoils, and
supersonic air inlets.
