  The self-similar decay of energy in a turbulent flow is studied in direct
numerical simulations with and without rotation. Two initial conditions are
considered: one non-helical (mirror-symmetric), and one with maximal helicity.
The results show that, while in the absence of rotation the energy in the
helical and non-helical cases decays with the same rate, in rotating flows the
helicity content has a major impact on the decay rate. These differences are
associated with differences in the energy and helicity cascades when rotation
is present. Properties of the structures that arise in the flow at late times
in each time are also discussed.
