title: Vortex-Breakdown-Induced Particle Capture in Branching Junctions.
abstract: We show experimentally that a flow-induced, Reynolds number-dependent particle-capture mechanism in branching junctions can be enhanced or eliminated by varying the junction angle. In addition, numerical simulations are used to show that the features responsible for this capture have the signatures of classical vortex breakdown, including an approach flow aligned with the vortex axis and a pocket of subcriticality. We show how these recirculation regions originate and evolve and suggest a physical mechanism for their formation. Furthermore, comparing experiments and numerical simulations, the presence of vortex breakdown is found to be an excellent predictor of particle capture. These results inform the design of systems in which suspended particle accumulation can be eliminated or maximized.
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Jesse T
authors: JT
authors: Ault
authors: Dipartimento di Scienze e Tecnologie Aerospaziali, Politecnico di Milano, 20156 Milano, Italy.
authors: Andrea
authors: A
authors: Fani
authors: Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, California 90089, USA.
authors: Kevin K
authors: KK
authors: Chen
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Sangwoo
authors: S
authors: Shin
authors: Laboratory of Fluid Mechanics and Instabilities, École Polytechnique Fédérale de Lausanne. EPFL-STI-IGM-LFMI, CH-1015 Lausanne, Switzerland.
authors: François
authors: F
authors: Gallaire
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Howard A
authors: HA
authors: Stone