Abstract
Signal analysis methods to educe organized vortex structures from random signal in turbulence are introduced here. Continuous wavelet was applied to detect flow separation from the velocity fluctuations on the surface of aerofoil with increase of attack angle. Continuous wavelet, Morlet wavelet, has the advantage to detect unsteady fluctuation over other signal analysis method. Organized vortex structures from numerical data of the supersonic mixing layer (Watanabe and Maekawa, 2004) were investigated using Proper Orthogonal Decomposition (POD). Lambda-shaped vortices were reconstructed as organized structure with high energy contribution in supersonic mixing layer by POD.
