Modal decomposition-based global stability analysis for reduced order modeling of 2D and 3D wake flows

摘要

The method for computation of stability modes for two- and three-dimensional flows is presented. The method is based on the dynamic mode decomposition of the data resulting from DNS of the flow in the regime close to stable flow (fixed-point dynamics, small perturbations about steady flow). The proposed approach is demonstrated on the wake flows past a 2D, circular cylinder, and a sphere. The resulting modes resemble the eigenmodes computed conventionally from global stability analysis and are used in model order reduction of the flow. The designed low-dimensional Galerkin model uses continuous mode interpolation between dynamic mode decomposition mode bases and reproduces the dynamics of Navier-Stokes equations. Copyright (c) 2015 John Wiley & Sons, Ltd.