Sedimentation, Orientation and Dispersal of Ramified Particles in a Turbulent Environment: ARO Research Area 1.1 Fluid Dynamics
Abstract
This project seeks to understand the motion of non-spherical particles that are settling in turbulent fluid flows. In a wide range of industrial and environmental situations, a turbulent fluid contains sedimenting particles whose shapes are far from spherical. Ice crystals in clouds, micro-organisms in bio-reactors, and wood fibers used in paper making are just a few examples. The settling and dispersal of these particles is strongly influenced by their alignment relative to the fluid flow and relative to the vertical direction. Most particles orient with their largest sides horizontal when they settling in still air, an orientation that minimizes their settling rates. However, turbulence causes particles to rotate and settle along a tortuous path. The research involves collaboration between Professor Donald Koch at Cornell University using numerical simulations and theory and Professor Greg Voth at Wesleyan University using experiments to explore the particle dynamics. The project focuses on particles made of several slender arms attached at the center, called ramified particles. This class of shapes allows the use of powerful theoretical tools from slender body theory to describe the coupling between particle-settling and turbulence induced fluid flows. Ramified shapes are also convenient for precision experimental measurement of the three dimensional position, orientation, and motion of individual particles using multiple cameras and advanced photogrammetry. A new vertical water tunnel facility will be developed to provide a controlled turbulent flow in which measurements will be performed on particles fabricated with 3D printing. This project seeks to develop quantitative understanding of non-spherical particle motion in order to allow prediction and control of particle orientation, settling and dispersal in a turbulent environment.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 14, 2016
- Source ID
- W911NF1510205
Entities
People
- Donald Koch
Organizations
- Army Contracting Command
- Cornell University
- United States Army