  Effects of the collision geometry on experimental observables that are known
to be sensitive to the high-density behavior of nuclear symmetry energy are
examined in U+U collisions at 0.52 GeV/nucleon using an isospin- and
momentum-dependent interaction within the framework of IBUU transport model. It
is found that the neutron-proton differential flow in tip-tip collisions and
the difference of neutron and proton elliptic flow in body-body collisions are
more sensitive to the symmetry energy at supra-saturation densities compared
with collisions of spherical nuclei of the same masses. In addition, the n/p
ratio of pre-equilibrium nucleons is found to be slightly more sensitive to the
symmetry energy in tip-tip collisions, and the collision geometry affects the
\pi^-/\pi^+ ratio significantly.
