  A new scenario for the interaction of a jet with a background medium with
cold clouds is investigated by means of hydrodynamic turbulence simulations
with cooling. The idea is that the cold clouds are overtaken by a radio cocoon
and stirred up by turbulence in this cocoon. The 2D multiphase turbulence
simulations contain all the three gas phases and have a number of interesting
properties. The produced power spectrum is proportional to the inverse square
of the wavevector. The Mach number - density relation may explain the observed
velocities in emission line gas associated with radio galaxies. The model also
explains the increased optical visibility within the radio structures, the
correlation between emission line and radio luminosity, and the evolution of
the alignment effect with source size. I also propose this to be a useful model
for the recently discovered neutral outflows in nearby radio sources.
