The Main Structure of Turbulent Boundary Layers

The structure of turbulent boundary layers on a flat plate is examined using flow visualization methods. The experimental results suggest that turbulent boundary layers consist of various kinds of instability waves. The main waves are T-S waves, G₁ waves and G₂ waves. The T-S wave is a large-scale two-dimensional wave produced as a result of the instability of the mean velocity distribution. The G₁ and G₂ waves are three-dimensional waves produced at the trough of T-S waves as a result of centrifugal instability.