  We explore use of the harmonic Einstein equations to numerically find
stationary black holes where the problem is posed on an ingoing slice that
extends into the interior of the black hole. Requiring no boundary conditions
at the horizon beyond smoothness of the metric, this method may be applied for
horizons that are not Killing. As a non-trivial illustration we find black
holes which, via AdS-CFT, describe a time-independent CFT plasma flowing
through a static spacetime which asymptotes to Minkowski in the flow's past and
future, with a varying spatial geometry in-between. These are the first
explicit examples of stationary black holes which do not have Killing horizons.
When the CFT spacetime slowly varies, the CFT stress tensor derived from
gravity is well described by viscous hydrodynamics. For fast variation it is
not, and the solutions are stationary analogs of dynamical quenches, with the
plasma being suddenly driven out of equilibrium. We find evidence these flows
become unstable for sufficiently strong quenches, and speculate the instability
may be turbulent.
