  The transonic phenomenon of black hole accretion and the existence of the
photon sphere are the characteristics of strong gravitational fields near a
black hole horizon. In this work, we study spherical accretion flow onto a
general parametrized spherically symmetric black hole spacetimes. For this
purpose, we analyze the accretion process of various perfect fluids, such as
the isothermal fluid of ultra-stiff, ultra-relativistic, and sub-relativistic
types and polytropic fluid, respectively. The influences of extra parameters
beyond the Schwarzschild black hole in the general parameterized spherically
symmetric black hole on the flow behaviors of the above-mentioned test fluids
are studied in detail. In addition, by studying the accretion of ideal photon
gas, we further discuss the correspondence between the sonic radius of
accreting photon gas and the photon sphere for the general parameterized
spherically symmetric black hole. Some possible future extensions of our
analysis are also discussed.
