  We study time evolution of sub-Keplerian transonic accretion flows onto black
holes using a general relativistic numerical simulation code. We perform
simulations in Schwarzschild spacetime. We first compare one-dimensional
simulation results with theoretical results and validate the performance of our
code. Next, we present results of axisymmetric, two-dimensional simulation of
advective flows. We find that even in this case, for which no complete
theoretical analysis is present in the literature, steady state shock formation
is possible.
