  Magnetic energy released in the corona by solar flares reaches the
chromosphere where it drives characteristic upflows and downflows known as
evaporation and condensation. These flows are studied here for the case where
energy is transported to the chromosphere by thermal conduction. An analytic
model is used to develop relations by which the density and velocity of each
flow can be predicted from coronal parameters including the flare's energy flux
$F$. These relations are explored and refined using a series of numerical
investigations in which the transition region is represented by a simplified
density jump. The maximum evaporation velocity, for example, is well
approximated by $v_e\simeq0.38(F/\rho_{co,0})^{1/3}$, where $\rho_{co,0}$ is
the mass density of the pre-flare corona. This and the other relations are
found to fit simulations using more realistic models of the transition region
both performed in this work, and taken from a variety of previously published
investigations. These relations offer a novel and efficient means of simulating
coronal reconnection without neglecting entirely the effects of evaporation.
