in the present work properties of rossby and inertia gravity waves are investigated based on proper orthogonal decomposition (pod) functions. the pod functions are constructed using analytical, experimental or numerical data recorded as snapshots. the pod basis can be carried out to make a reduced order model by galerkin projection of governing equations onto these functions. in this paper, the...

The derivations of existing error bounds for reduced order models of time varying partial differential equations (PDEs) constructed using proper orthogonal decomposition (POD) have relied on bounding the error between the POD data and various POD projections of that data. Furthermore, the asymptotic behavior of the model reduction error bounds depends on the asymptotic behavior of the POD data ...

Capability of the Proper Orthogonal Decomposition (POD) method in extraction of the coherent structures from a spatio-temporal chaotic field is assessed in this paper. As the chaotic field, an ensemble of 40 snapshots, obtained from Direct Numerical Simulation (DNS) of the Kuramoto-Sivashinsky (KS) equation, has been used. Contrary to the usual methods, where the ergodicity of the field is need...

A Proper Orthogonal Decomposition (POD) is constructed for a Mach 0.9 turbulent jet using a well-validated direct numerical simulation database. Norms are defined based on near-field volume integrals of pressure, turbulence kinetic energy, streamwise velocity, and total enthalpy, two-dimensional integrals of streamswise velocity (to match experimental measurements), and far-field integrals of p...

Reduced-order models of the flow in a plane channel flow are constructed in two regimes: a minimal flow unit in which turbulence is sustained, and a transitional flow linearized about the laminar profile. Proper orthogonal decomposition (POD) of data from a direct numerical simulation of a channel flow in a minimal flow unit is performed in order to examine the coherent structures and their dyn...

We use POD and EPOD (extended POD) analysis to extract the main features of the flow over a thick flat plate simulated with a LES. Our goal is to better understand the coupling between the velocity field and the surface pressure field. We find that POD modes based on the full velocity and energy fields contain both flapping and shedding frequencies. Pressure modes are found to be uniform in the...

Proper orthogonal decomposition (POD) is applied to the direct numerical simulation (DNS) of a turbulent boundary layer performed by Wu & Moin (2010), and the resulting POD modes of various scales are examined. The modes include structures resembling those observed in instantaneous flow fields, such as large-scale motions of streamwise velocity with ramp-like wall-normal growth. Other modes cor...