Particle tracking velocimetry and trajectory curvature statistics for particle-laden liquid metal flow in the wake of a cylindrical obstacle

This paper presents the analysis of particle-laden liquid metal flow around a cylindrical obstacle at different obstacle Reynolds numbers. Particles in liquid metal are imaged using dynamic neutron radiography. We present the results of particle tracking velocimetry of the obstacle wake flow and demonstrate the capabilities to assess both temporal and spatial characteristics of turbulent liquid metal flow, validating our methods against theoretical expectations, numerical simulations and experiments reported in the literature. We obtain the expected linear 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. To our knowledge, this is the first such result for liquid metals. 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 plan for further research using neutron imaging of particle-laden flow.