Over the last 30 years, turbulent entrainment has come to be viewed as a large-scale
process, directed by coherent structures, and described as engulfing. With turbulence
simulations, we examined the process of entrainment directly, as growth of vorticity and
concentration along fluid particle pathlines which were computed simultaneously. Our
results indicate that the process is more often small scale. Growth occurs close to the
turbulence boundary, within small radial displacements, and in times which are smaller than …