  The velocity gradient tensor can be decomposed into axial straining, pure
shearing, and rigid rotation tensors, each with distinct symmetry and normality
properties. We partition the strength of velocity gradient fluctuations based
on the relative contributions of these constituents in several turbulent flows.
These flows include forced isotropic turbulence, channels and boundary layers,
and subsonic and transonic jets. For forced isotropic turbulence, the
partitioning is in excellent agreement with previous results. For wall-bounded
turbulence, the partitioning collapses onto the isotropic partitioning far from
the wall, where the mean shearing is relatively weak. By contrast, the
near-wall partitioning is dominated by shearing. Between these two regimes, the
partitioning collapses well at sufficiently high friction Reynolds numbers and
its variations in the buffer layer and the log-law region can be reasonably
modeled as a function of the mean shearing strength. The isotropic partitioning
also applies throughout much of the turbulent jets due to the rapid decay of
the mean flow shear layer near the nozzle lip. Before reaching the exterior
potential flow regime, the relative contribution of rigid rotation around the
turbulent/non-turbulent interface is enhanced with respect to the isotropic
partitioning. Altogether, our results highlight the broad applicability of the
velocity gradient partitioning to turbulence modeling.
