Corso, Pascal; Obrist, Dominik (April 2023). Study of the kinetic energy anisotropy over spherical shells downstream of stenotic and bioprosthetic aortic valves (Unpublished). In: 22nd Computational Fluids Conference (CFC23). Cannes (France).
Haemodynamic transition-to-turbulence due to aortic stenoses or non-optimal bioprosthetic aortic valves (BioAVs) may contribute to a variety of pathophysiological effects (Stein & Sabbah, 1976). Therefore, the thorough study of the behaviour of large-scale eddies, of their interactions with laminar regions and of their spatio-temporal distribution is fundamental to elucidate how turbulence is triggered and develops in aortic flows at peak systole. We thus intend to investigate the anisotropy in the modal kinetic energy carried by the flow structures at various wavenumbers over time. The anisotropy intensity is calculated over equispaced spherical shells placed in the vicinity of the valve orifice. To conduct such a study, data are obtained from a direct numerical simulation of the incompressible flow downstream of a fixed-wall aortic stenosis (Corso et al., 2021) using a high-order spectral element Navier-Stokes solver (Fischer et al., 2008) and from three-dimensional fluid-structure interaction (FSI) simulations of BioAVs with unstably moving leaflets (Nestola et al, 2019). With regard to the spatial distribution of the anisotropy intensity, in the stenotic case, the region where the flow velocity is smaller (that is, outside of the jet) is characterised by high anisotropy intensity values, which is a direct consequence of the highly asymmetric and eccentric stenotic orifice. In the case of the BioAVs with moving leaflets, the highest intensities are found close to the leaflets’ free edges as a result of the time-varying orifice area. It is also noted that the ring post of the bioprosthetic valve tends to be aligned with peaks in the anisotropy field. The novelty in this work lies in the method developed to quantify the anisotropy in the kinetic energy for complex flows as the ones found downstream of the investigated aortic valve configurations. The conclusions drawn are instrumental for the improvement of BioAVs design.
Item Type: |
Conference or Workshop Item (Speech) |
|---|---|
UniBE Contributor: |
Corso, Pascal, Obrist, Dominik |
Subjects: |
600 Technology > 610 Medicine & health 600 Technology > 620 Engineering |
Language: |
English |
Submitter: |
Pascal Corso |
Date Deposited: |
31 Aug 2023 09:32 |
Last Modified: |
16 Jan 2024 20:43 |
Related URLs: |
|
Additional Information: |
Talk designed and given by P. Corso. |
Uncontrolled Keywords: |
Aortic Stenosis, Bioprosthetic Aortic Valves, Fluid-Structure Interaction Simulations, Haemodynamic, Kinetic Energy Anisotropy, Valve Design |
URI: |
https://boris.unibe.ch/id/eprint/185921 |
Actions (login required)
 |
Edit item |