Unsteady Simulation and Mode Analysis of Disturbed Cylinder Flow

Abstract

The unsteady simulation of cylinder flow with inlet velocity disturbance is simulated and compared with that without disturbance. POD is adopted to analyze and capture the dominant modes of the vortex street in the cylinder wake. The results show that the POD method is efficient in reconstructing the flow field. When the inlet velocity disturbance exists, the number of modes required to reconstruct the flow field accurately is almost unchanged, but the energy proportion of each mode changes. The larger the disturbance frequency is, the smaller the shape and vorticity magnitude of the vortex street is, and the slower the generation speed is. If the frequency deviates too much from the original frequency of the flow field, the effect of inlet velocity disturbance will be shielded.