Role of inertia in the interaction between oscillatory flow and a wall-mounted leaflet

The recognition of phenomena emerging from fluid-structure interaction represents a central problem in applied fluid mechanics, especially relevant in those biological systems when the tissue properties are not measurable with accuracy. The problem of an oscillatory flow over a wall-mounted leaflet is studied here with the objective to better define the role of inertia. A numerical model based on time-dependent conformal transformation is introduced to ensure an accurate solution and an intrinsic fluid-solid coupling. The results evidence the development of long wave modulation whose amplitude and frequency depend on the leaflet inertia. When inertia is above a certain threshold, the modulation becomes large enough that the leaflet ends impacting on the wall. The potential relevance in terms of mechanical valves design, or long-term testing of natural systems subjected to period forcing, is briefly discussed.