DOI: 10.1615/TSFP5
NUMERICAL STUDY OF VORTEX RING EVOLUTION AND INTERACTION WITH A FREE SURFACE
Краткое описание
Direct Numerical Simulation (DNS) is used to evolve two initially laminar vortex rings, of differing core thickness, through transition to the turbulent regime. We investigate the vortical structure which defines the respective phases and give an account of the turbulent breakdown process. The structure of the resultant turbulent ring is found to be different for the thin- and thick-core rings. The thin-core ring maintains a coherent core structure whereas the thick-core becomes a swirling mass of vorticity filaments. Using the vorticity field as an initialisation, we investigate the surface interaction of vortex rings in a laminar, transitional and turbulent state. We find characteristic surface deformations and vorticity reconnections specific to the condition of the ring.