On flow unsteadiness induced by structural vibration

In this paper, the effects of structural vibration on flow unsteadiness are investigated numerically. A fully coupled model, that solves the unsteady flow equations as well as the dynamic equations of the structure, is used. Numerical experiments are carried-out for flow over a backward-facing step, where a large number of numerical and experimental data exist for comparisons. The flexible structure is upstream of the step and is excited by a plane acoustic wave from the side opposite to the flow. Three Reynolds number cases are studied: 300 for a laminar flow, 3000 for a transitional flow and 15 000 for a turbulent flow. The results obtained are in good agreement with experimental observations and show the strong coupling between structural vibration and the resulting flow unsteadiness.