2010

Algorithm for Stabilizing a POD-Based Dynamical System

This algorithm provides a new way to improve the accuracy and asymptotic behavior of a low-dimensional system based on the proper orthogonal decomposition (POD). Given a data set representing the evolution of a system of partial differential equations (PDEs), such as the Navier-Stokes equations for incompressible flow, one may obtain a low-dimensional model in the form of ordinary differential equations (ODEs) that should model the dynamics of the flow. Temporal sampling of the direct numerical simulation of the PDEs produces a spatial time series. The POD extracts the temporal and spatial eigen-functions of this data set. Truncated to retain only the most energetic modes followed by Galerkin projection of these modes onto the PDEs obtains a dynamical system of ordinary differential equations for the time-dependent behavior of the flow.

In practice, the steps leading to this system of ODEs entail numerically computing first-order derivatives of the mean data field and the eigenfunctions, and the computation of many inner products. This is far from a perfect process, and often results in the lack of long-term stability of the system and incorrect asymptotic behavior of the model. This algorithm describes a new stabilization method that utilizes the temporal eigen-functions to derive correction terms for the coefficients of the dynamical system to significantly reduce these errors.

This work was done by Virginia L. Kalb of Goddard Space Flight Center. For further information, contact the Goddard Innovative Partnerships Office at (301) 286-5810. GSC-15129-1

White Papers

Introduction to Hypervisor Technology
Sponsored by Curtiss-Wright Controls Embedded Computing
X-Ray Imaging: Emerging Digital Technology - CMOS Detectors
Sponsored by Teledyne DALSA
Simulation of the ballistic perforation of aluminum plates with Abaqus/Explicit
Sponsored by Simulia
Expanding GNSS Testing with Multiple Synchronized Signal Recorders
Sponsored by Averna
Back to Basics of Electrical Measurement
Sponsored by Keithley
Linear Motors Application Guide
Sponsored by Aerotech

White Papers Sponsored By: