The flow properties of confined vortex matter driven through disordered
mesoscopic channels are investigated by mode locking (ML) experiments. The
observed ML effects allow to trace the evolution of both the structure and the
number of confined rows and their match to the channel width as function of
magnetic field. From a detailed analysis of the ML behavior for the case of
3-rows we obtain ({\it i}) the pinning frequency fp, ({\it ii}) the onset
frequency fc for ML (∝ ordering velocity) and ({\it iii}) the
fraction LML/L of coherently moving 3-row regions in the channel. The
field dependence of these quantities shows that, at matching, where LML is
maximum, the pinning strength is small and the ordering velocity is low, while
at mismatch, where LML is small, both the pinning force and the ordering
velocity are enhanced. Further, we find that fc∝fp2, consistent
with the dynamic ordering theory of Koshelev and Vinokur. The microscopic
nature of the flow and the ordering phenomena will also be discussed.Comment: 10 pages, 7 figure, submitted to PRB. Discussion has been improved
and a figure has been adde