This photo shows a flow visualization of a turbulent boundary layer at Mach 2.8. The direction of flow is from right to left. In nature, the boundary layer between a surface and a fluid is usually turbulent but impossible to see. The visualization represents an instantaneous snapshot of the flow. Turbulence is known for its intermittency–its strong variation in time–a characteristic that is clear just from comparing the two snapsnots. #
Turbulence Near the Wall
