  The appearance of detached recirculation regions in wakes with base bleed
determines the aerodynamic properties of many natural organisms and
technological applications. In this work we introduce an analytical model which
captures certain key dimensions of the recirculation region in the wake of
porous plates of infinite aspect ratio, along with the porosity range \ks{over
which} it exists, when vortex shedding is absent or suppressed. The model is
used to interpret why the recirculation region (i) emerges, (ii) migrates away
from the body with increasing base bleed, (iii) disappears at a critical bleed
and (iv) is partially insensitive to variations in the Reynolds number. The
model predictions show considerable agreement with data from laboratory
experiments and numerical simulations. exists. The predictions show
considerable agreement with data from laboratory experiments and numerical
simulations.
