Quadrant and conditional analyses of non-spherical particle segregation in a turbulent channel flow

Turbulent flows transporting particles of different sizes and shapes can be found in many natural and industrial systems. In understanding such flows, it is important to identify the mechanisms responsible for the dispersion, segregation and deposition on solid surfaces of particles with different shapes, and of specific interest here how such particles interact with near-wall coherent turbulent structures (outward motion, ejection, inward motion and sweep). Results from large eddy simulation coupled with Lagrangian particle tracking are used together with conditional statistics (probability density function and scatter plots) in quadrants to study the distribution of fluid, particle and slip velocity fluctuations. The results, though challenging to analyse, give insight into the values of the quadrants and how these distributions reveal the mechanisms responsible for particle segregation in the near-wall region. (C) 2015 The Authors. Published by Elsevier Ltd.