Physical simulation experiments of momentum transport associated with advecting vortical motions

Abstract

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 that involved perturbing laminar vortex rings by altering the natural advection velocity of the ring. Purely advective perturbations to the ring result in a momentary amplification of the Reynolds stress that subsequently decreases back to the u..