In this paper, the proper orthogonal decomposition (POD) and dynamic mode
decomposition (DMD) are applied to analyze the 3D late transitional flow on the flat plate
obtained from direct numerical simulation (DNS). POD is used to find the most persistent
spatial structures while DMD is used to find single frequency modes. The Omesga
method is applied as a vortex identification to visualize vortices with isosurfaces Ω =
0.52. The results in POD and DMD are discussed and compared to show the same and
different features such as shapes, amplitudes and time evolutions.
Keywords: Dynamic mode decomposition, Identification method, Modal
decomposition, Late flow transition, Omega method, Proper orthogonal
decomposition.