  This paper describes a multidimensional hydrodynamic code which can be used
for studies of relativistic astrophysical flows. The code solves the special
relativistic hydrodynamic equations as a hyperbolic system of conservation laws
based on the total variation diminishing (TVD) scheme. It uses a new set of
conserved quantities and employs an analytic formula for transformation from
the conserved quantities in the reference frame to the physical quantities in
the local rest frame. Several standard tests, including relativistic shock
tubes, a relativistic wall shock, and a relativistic blast wave, are presented
to demonstrate that the code captures discontinuities correctly and sharply in
ultrarelativistic regimes. The robustness and flexibility of the code are
demonstrated through test simulations of the relativistic Hawley-Zabusky shock
and a relativistic extragalactic jet.
