DOI: 10.1615/TSFP8
PHYSICAL SIMULATION EXPERIMENTS OF MOMENTUM TRANSPORT ASSOCIATED WITH THE EVOLUTION OF ADVECTING VORTICAL MOTIONS
摘要
We report on experiments investigating velocity-vorticity interactions that underlie the mechanisms of turbulent inertia associated with advecting regions of concentrated vorticity. To isolate mechanisms and expose the full scope of possible interactions, unsteady laminar flow experiments are conducted. These experiments mimic instantaneous flow field interactions known to exist in turbulent wall-flows. Experiments are conducted in a large water tank. These studied vortex ring interactions with wall effects, a Stokes layer, and imposed advection velocity. Purely advective perturbations to the ring do not introduce any asymmetries whereas interactions with a shear-layer and rings directed towards a wall at a slight angle introduce asymmetries. Shear-layer interactions cause significant asymmetries. This induces a source or sink of momentum in the ring depending upon the sign of spanwise vorticity in the shear-layer.