Numerical Investigation of Flow around Two Tandem Cylinders in the Upper Transition Reynolds Number Regime Using Modal Analysis

Flow around two tandem cylinders at Re = 3.6 × 106 for different center-to-center spacing ratio (L/D) is investigated numerically using two-dimensional (2D) Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations combined with a standard k−ω SST turbulence model. The instantaneous flow structures the cylinders, hydrodynamic forces on and Strouhal number (St) are analyzed discussed. Dynamic Mode Decomposition (DMD) used to extract spatiotemporal information of coherent in wake regions behind upstream (UC) downstream (DC) cylinders. A sparsity-promoted algorithm implemented select dominant modes which contribute most dynamics system. Based modes, reduced-order representation flows built. comparison lift drag force–time histories, obtained by simulation results representations, shows high capability latter reproduce surrounding properties Reynolds number.