Transversely homogeneous, uniformly sheared, turbulent flow was
allowed to reach its
asymptotic structure in a straight wind tunnel section and then it was
passed through
a sequence of two curved sections and a final straight section. The cross-sectional
shape of the entire wind tunnel was rectangular, while the two curved sections
had
circular centrelines with the same radius but opposing curvatures. In all
cases, the
mean strain rate due to curvature was relatively weak (±5%), compared
to the mean
shear rate, but its effects on the turbulence kinetic energy and structure
were substantial;
streamwise pressure gradient effects were negligible. The turbulence structure
approached approximately self-similar states towards the downstream ends
of each
curved section but the main interest of the present study was the rate
of adjustment
of the turbulence following a stepwise change in curvature. It has been
shown that the
adjustment of the shear stress anisotropy, which is a sensitive indicator
of structural
changes, can be approximated by a first-order system response, whose time
constant
scales with the inverse mean shear and is independent of the curvature
parameter. Uniformly
sheared flow results were used for an interpretation of the structure of
curved
turbulent boundary layers, both during adjustment and in a fully developed
state.