Dissipation scale and control of fine-scale turbulence in a plane mixing layer

The entrainment of fluids from two streams into the shear region of an incompressible mixing layer is dominated by the evolution of large coherent structures. However, fine-scale mixing of the entrained fluids mainly occurs at the interfaces of the small-scale turbulence. In this investigation, experiments were conducted to understand the properties of the small scales and to explore a method for controlling the population of the fine-scale turbulence. Furthermore, a dissipation scale, zeta, is found from the zero-crossing of the time derivative of the velocity fluctuations. This scale characterizes the most probable size of fine-scale turbulence, which produces most of the viscous dissipation.