Fluid–structure interaction for mechanical filament valve mimicking a biological leaflet valve

Abstract

The biological leaflet valve is a structure found in blood vessels and the cardiac system, designed to maintain a unidirectional flow within the vessels. Two filaments inspired by the biological leaflet are installed inside the channel, and behavior of two filaments is explored by using immersed boundary method. It is observed that the filaments serve as a valve, maintaining the unidirectional flow inside the channel depending on the length (L) and the initial inclined angle (θ) of the filaments. The behavior of the filaments is classified into three modes based on the flow characteristics around the filaments. The pressure and vorticity fields in the vicinity of the filaments are examined to investigate the influence of the surrounding flow on the behavior of filaments. The present study reveals the time sensitivity of valve response, the power consumption, and hydrodynamic efficiency (ηV,steady) of the filament valve, noting that the response speed of the filament valve can vary up to 2.5 times depending on L and θ. The dynamic behavior of the filament valve is analyzed with respect to changes in the properties of the filaments, observing a monotonic decrease in hydrodynamic efficiency with an increase in the bending rigidity (γ) of the filaments. As a result, the present study will be employed as a cornerstone in the development of a mechanical system that emulate biological structures through biomimetics.