  The rate of reconnection characterizes how quickly flux and mass can move
into and out of the reconnection region. In the Terrestrial Reconnection
EXperiment (TREX), the rate at which antiparallel asymmetric reconnection
occurs is modulated by the presence of a shock and a region of flux pileup in
the high-density inflow. Simulations utilizing a generalized Harris-sheet
geometry have tentatively shown agreement with TREX's measured reconnection
rate scaling relative to system size, which is indicative of the transition
from ion-coupled toward electron-only reconnection. Here we present simulations
tailored to reproduce the specific TREX geometry, which confirm both the
reconnection rate scale as well as the shock jump conditions previously
characterized experimentally in TREX. The simulations also establish an
interplay between the reconnection layer and the Alfv\'enic expansions of the
background plasma associated with the energization of the TREX drive coils;
this interplay has not yet been experimentally observed.
