  Within an advanced Langevin-hydrodynamics framework coupled to a hybrid
fragmentation-coalescence hadronization model, we study heavy flavor quenching
and flow in relativistic heavy-ion collisions. We investigate how the initial
heavy quark spectrum, the energy loss and hadronization mechanisms of heavy
quarks in medium, the evolution profile of pre-equilibrium stage, the flow of
medium and the temperature dependence of heavy quark diffusion coefficient
influence the suppression and elliptic flow of heavy mesons at RHIC and the
LHC. Our result shows that different modeling of initial conditions,
pre-equilibrium evolution and in-medium interaction can individually yield
about 10-40% uncertainties in D meson suppression and flow at low transverse
momentum. We also find that a proper combination of collisional versus
radiative energy loss, coalescence versus fragmentation in hadronization, and
the inclusion of medium flow are the most important factors for describing the
suppression and elliptic flow of heavy mesons.
