  Reynolds Averaged Navier Stokes (RANS) models represent the workhorse for
studying turbulent flows in industrial applications. Such single-point
turbulence models have limitations in accounting for the influence of the
non-local physics and flow history on the evolution of the turbulent flow. In
this context, we investigate the sensitivity inherent to single-point models
due to their characterization of the internal structure of homogeneous
turbulent flows solely by the means of the Reynolds stresses. For a variety of
mean flows, we study the prediction intervals engendered due to this
coarse-grained description. The nature of this variability and its dependence
on parameters such as the mean flow topology, the initial Reynolds stress
tensor and the normalized strain rate is identified, analyzed and explicated.
The ramifications of this variability on the formulation of classical RANS
closure models are highlighted.
