<div>This study investigates the flow characteristics in the test section of a
model-scale, three-quarters open-jet, closed-loop return wind tunnel equipped
with a novel device featuring three subsystems to generate transient yaw, gusts,
and turbulence. The effect of each subsystem on the resulting turbulent and
unsteady flows is evaluated individually and simultaneously. It is demonstrated
that this new turbulence generation system can generate yaw distributions with
standard deviations ranging from 2.1° to 8.0°. This replicates a wide range of
on-road yaw behavior. Additionally, the subsystems can activate transient yaw
events and unsteady gusts. Frequency sweeping was demonstrated to fill a wide
range of low-frequency spectra, which helps recreate the on-road flow spectra in
wind tunnels. Unsteady gusts of more than 15% of the mean flow velocity were
achieved. The active turbulence subsystem generates turbulence levels from a few
percent, passively, to over 20% intensity levels actively, with tailorable
levels depending on input parameters to the active grid. Combined, the
subsystems were demonstrated to achieve a wide range of yaw distributions with
different standard deviations and features of the on-road turbulence spectrum,
from low-frequency events to broadband turbulence with significant inertial
subrange within the model-scale wind tunnel.</div>