Numerical analysis on flow around a wall-mounted square structure using Dynamic Mode Decomposition

Abstract

Numerical investigations of the flow around a wall-mounted square structure have been carried out by using three-dimensional Spalart-Allmaras Delayed Detached Eddy Simulations (SADDES). The Reynolds number based on the free-stream velocity and the height of the structure is 1.19 x 10/5. The instantaneous hydrodynamic quantities are analyzed. The time-averaged results of the velocities, the Reynolds-averaged statistics and the vortical structures are presented and discussed. Dynamic Mode Decomposition (DMD) is applied to study the flow in the wake region behind the square structure. The dynamically important modes are extracted by further using a sparsity-promoted algorithm. The temporal information of the modes is compared with the results of the frequency analysis. The reduced order model of the flow field is constructed by the modes and shows good agreement with the numerical simulation results.