  This paper develops the high-order accurate entropy stable finite difference
schemes for one- and two-dimensional special relativistic hydrodynamic
equations. The schemes are built on the entropy conservative flux and the
weighted essentially non-oscillatory (WENO) technique as well as explicit
Runge-Kutta time discretization. The key is to technically construct the
affordable entropy conservative flux of the semi-discrete second-order accurate
entropy conservative schemes satisfying the semi-discrete entropy equality for
the found convex entropy pair. As soon as the entropy conservative flux is
derived, the dissipation term can be added to give the semi-discrete entropy
stable schemes satisfying the semi-discrete entropy inequality with the given
convex entropy function. The WENO reconstruction for the scaled entropy
variables and the high-order explicit Runge-Kutta time discretization are
implemented to obtain the fully-discrete high-order schemes. Several numerical
tests are conducted to validate the accuracy and the ability to capture
discontinuities of our entropy stable schemes.
