Dispersion of fine particles in turbulent flow
Particle-Laden Turbulence is prevalent in nature and engineering applications - dust in atmosphere, river sedimentation, cyclone separators, coal furnace, and electrostatic precipitators, etc. The distribution of particles suspended in such gases or liquids must take into account not only the size and density of the particles, but also the hydrodynamic properties such as flow velocity, space/time scale, and fluid viscosity. Especially, the 'Preferential Concentration' phenomenon, in which the particles are heterogeneously distributed under certain turbulent conditions, increases the collision rate of the particles and affects the physical properties of the particles. Our team mainly focuses on the characteristics of particles distribution in various flow structures including homogeneous isotropic turbulence (HIT) and synthetic jet. In addition, by studying the relationship between the humidity conditions of turbulence and the distribution of particles, we expect explanations on how the atmospheric humidity affects the concentration of fine dust in the atmosphere.
The following is a sample instataneous particle distribution field, which is taken from a homogeneous isotropic turbulence using a continuous wave laser and a high speed camera. The distribution of particles can be analyzed using Voronoin analysis, which divides the image into polygons corresponding to one particle. In the Voronoi analysis, dark gray and light gray are classified as clusters and voids, respectively.
