Reduced order models for wake flows at low Reynolds numbers

3. J. D'ADAMO, A. CAMILLERI, G. ARTANA

San Carlos, Brasil

Workshop; Escola de Transicao e Turbulenca; 2008

ABCM

We present in this work a way to construct reduced order models (ROM) for wake flows at low Reynolds numbers, from Particle Image Velocimetry (PIV) data. The proper orthogonal decomposition method (POD) allows the extraction of a few number of functions or modes that describe the flow’s velocity field. Galerkin projection of Navier Stokes equation onto these modes leads to obtain a system of ordinary non linear equations. The sole dimension reduction from Galerkin procedure does not assure the convergence and stability of solutions. Several methods have been proposed[13][3][9].to deal with this problem. On the other hand, recent studies on hydrodynamic stability in wake flows[2][20] suggest model modifications on the POD-Galerkin ROM. In this context we propose data assimilation and center manifold theory to achieve improvements for the POD-based ROM from PIV experimental data. The method is also validated with results on direct numerical simulations( DNS), free from experimental noise.