Abstract

Mitral regurgitation is the most common valvular insufficiency and Edge-to-Edge Repair (ETER) is a common treatment. This research looks at simplified orifice configurations referred to as Single-Orifice (SO), Symmetric Double-Orifice (SDO) and Asymmetric Double-Orifice (ADO). This research builds on previous experiments performed by Anna Chtchetinina, the data collected are here further post-processed in order to reveal several critical flow characteristics. In the experiments, the unbounded flow is generated through a piston-cylinder setup and time-resolved particle image velocimetry is used for flow measurements. The velocity fields are extracted using a commercial software and then processed using custom-made codes.
Time-averaged velocity profiles of all the configurations show that the two jets merge at the downstream. Also, the investigation on the path of the vortices in the single-orifice configurations displays a steady streamwise velocity of the core through the experiments. The results obtained from analysing energy loss and time-frequency indicate that the symmetric double-orifice presents the most energy dissipation and turbulence among all the configurations. Proper Orthogonal Decomposition (POD) revealed that the asymmetric configuration requires the least number of modes to be reconstructed up to the desired level of energy. POD applied to the strain rate showed that most of the dissipation in single-orifice configuration is present around the center of the vortices.