  This paper presents the analysis of the particle-laden liquid metal wake flow
around a cylindrical obstacle at different obstacle Reynolds numbers. Particles
in liquid metal are visualized using dynamic neutron radiography. We present
the results of particle tracking velocimetry of the obstacle wake flow using an
improved version of our image processing and particle tracking code MHT-X. The
latter now utilizes divergence-free interpolation of the particle image
velocimetry field used for motion prediction and particle trajectory
reconstruction. We demonstrate significant improvement over the previously
obtained results by showing the capabilities to assess both temporal and
spatial characteristics of turbulent liquid metal flow, and validating the
precision and accuracy of our methods against theoretical expectations,
numerical simulations and experiments reported in literature. We obtain the
expected vortex shedding frequency scaling with the obstacle Reynolds number
and correctly identify the universal algebraic growth laws predicted and
observed for trajectory curvature in isotropic homogeneous two-dimensional
turbulence. Particle residence times within the obstacle wake and velocity
statistics are also derived and found to be physically sound. Finally, we
outline potential improvements to our methodology and plans for further
research using neutron imaging of particle-laden flow.
