Large Eddy Simulation Turbulence Most flows occurring in nature are turbulent.
Turbulence occurs in many kinds of flows and is used in many processes for positive purposes.
Laminar flow is always the exception. Turbulence is an eddying motion that exist at high Reynolds numbers. Turbulence has a wide spectrum of eddy sizes with a corresponding spectrum of fluctuation frequencies. Turbulence has prevailing rotational motion that can be thought of as a tangle of vortex elements with highly unsteady vorticity vectors that are aligned in all directions. The largest eddies have sizes on the same order of magnitude as the flow domain, have low frequencies, and are effected by the boundaries and the mean flow.