4. Structure-fluid coupling in flow

We are now considering a vibrating structure (i.e. one that is always animated by small movements) in the presence of a continuously flowing fluid, which is the case for most industrial applications.

The problem of modeling fluid-structure interaction then becomes much more complex. In fact, the (fixed-wall) flows encountered in practice are in fact very complex: the velocity field comprises an average part, but also a fluctuating turbulent or unsteady part. Significant gradients are observed in the boundary layer. Boundary layer detachment is possible, etc.

These are all characteristics of high Reynolds number flows.

The existence of wall vibration only complicates the problem. Experimental observations show opposite behavior from one case to another. For example, vibration damping can increase with flow velocity,...