  An energy-based discontinuous Galerkin method for the advective wave equation
is proposed and analyzed. Energy-conserving or energy-dissipating methods
follow from simple, mesh-independent choices of the inter-element fluxes, and
both subsonic and supersonic advection is allowed. Error estimates in the
energy norm are established, and numerical experiments on structured grids
display optimal convergence in the $L^2$ norm for upwind fluxes. The method
generalizes earlier work on energy-based discontinuous Galerkin methods for
second order wave equations which was restricted to energy forms written as a
simple sum of kinetic and potential energy.
