  Hydraulic jumps are oftentimes encountered in natural and human-made
environments. The transition from supercritical to subcritical flow involves
large energy dissipation rates and substantial air entrainment, preventing the
use of monophasic flow measurement instrumentation. This paper presents an
experimental study of a stable hydraulic jump with a Froude number of 4.25,
utilizing novel intrusive phase-detection probe techniques and image-based
velocimetry from a side perspective. Turbulence estimations were obtained for
the impinging region and the roller region of the jump including Reynolds
stresses, turbulent integral scales and velocity fluctuations spectra. The
velocity spectra had a -5/3 slope in the inertial subrange and flattened at
larger frequencies. This is thought to be linked to an energy transfer from the
inertial range to the frequencies associated with bubble scales. Overall, the
collected data is of particular interest for high-fidelity numerical model
validation and the study represents an advancement in air-water flow research.
