We introduce a new troubled-cell indicator for the
discontinuous Galerkin (DG) methods for solving
hyperbolic conservation laws.
This indicator can be defined on unstructured meshes for
high order DG methods and depends only on data from the
target cell and its immediate neighbors.
It is able to identify shocks without PDE sensitive
parameters to tune.
Extensive one- and two-dimensional simulations on the
hyperbolic systems of Euler equations
indicate the good performance of this new troubled-cell
indicator coupled with a simple minmod-type TVD limiter
for the Runge-Kutta DG (RKDG) methods.