Opening of a wall-mounted leaflet by a single flow pulse

Area of Science:

• Fluid dynamics
• Computational mechanics
• Biomechanics

Background:

• Understanding fluid-structure interactions is crucial for designing systems involving moving components in flows.
• Leaflet dynamics are complex, influenced by fluid forces and the leaflet's physical properties.

Purpose of the Study:

• To investigate the fluid-structure interaction during the opening of a rigid leaflet driven by flow pulsation.
• To analyze the influence of leaflet inertia and flow parameters (Strouhal number) on leaflet motion and vortex formation.

Main Methods:

• Numerical integration of the Navier-Stokes equations coupled with rigid body dynamics.
• Simulation of a simplified system: a rigid leaflet initially vertical on a horizontal wall subjected to flow pulsation.

Main Results:

• High leaflet inertia significantly restricts motion caused by flow pulsation.
• Low leaflet inertia leads to increased opening with decreased Strouhal numbers (longer periods or higher velocities).
• A critical intermediate inertia range exists where the leaflet fully opens and impacts a surface at high speed.

Conclusions:

• Leaflet inertia and Strouhal number are critical parameters governing fluid-structure interaction dynamics.
• The study reveals distinct regimes of leaflet behavior based on inertia, including a high-speed impact scenario.
• Findings provide insights into the control of leaflet motion in pulsatile flows.