“…Villalba et al (2012) revealed the weak tendency of particles aligning in the streamwise direction, even if they were released homogeneously into the flow field. For the further review, see Monchaux et al (2012), Uchiyama and Shimada (2014), and Kartushinsky et al (2014). The above researches were mainly performed in wall turbulence without considering the wall permeability and its effects on particle dispersion.…”