  The transport of independent active Brownian particles within a
two-dimensional narrow channel, modeled as an open-wedge, is studied both
numerically and theoretically. We show that the active force tends to localize
the particles near the walls thus reducing the effect of the entropic force
which, instead, is prevailing in the case of passive particles. As a
consequence, the exit of active particles from the smaller side of the channel
is facilitated with respect to their passive counterpart. By continuously
re-injecting particles in the middle of the wedge, we obtain a steady regime
whose properties are investigated with and without the presence of an external
constant driving field. We characterize the statistics and properties of the
exit process from the two opposite sides of the channel, also by making a
comparison between the active and passive case. Our study reveals the existence
of an optimal value of the persistence time of the active force which is able
to guarantee the maximal efficiency in the transport process.
