  We study the collision energy dependence of elliptic flow v_2 and triangular
flow v_3 in Au+Au collisions within the energy range sqrt(s_{NN}) = 5-200 GeV,
utilizing a transport + hydrodynamics hybrid model. The transport part is
described by the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) approach,
combined with an intermediate (3+1)-dimensional ideal hydrodynamical evolution
phase using a chiral model equation of state. We find the decrease of v_2
produced by hydrodynamics at lower collision energies partially compensated by
the transport dynamics. This does not apply to v_3, which falls to 0 in
midcentral collisions at sqrt(s_{NN}) = 5 GeV. We conclude that the triangular
flow provides the clearer signal for the formation of low-viscous fluid in
heavy ion collisions.
