  We study the role of adiabatic index in determining the critical points in
the transonic low angular momentum accretion flow onto a black hole. We present
the general relativistic 2D hydrodynamic simulations of axisymmetric, inviscid
accretion flows in a fixed Kerr black hole gravitational field. A relativistic
fluid where its bulk velocity is comparable to the speed of light, flowing in
the accretion disk very close to the horizon can be described by an adiabatic
index of 4/3 < {\gamma} < 5/3. The time dependent evolution of the shock
position and respective effects on mass accretion rate and oscillation
frequency with varying adiabatic index is discussed in the context of the
observed microquasars.
