Tese: Numerical study of the influence of tilt valve angle on blood flow in an aortic model
Aluno(a) : Diego Fernando Celis TorresOrientador(a): Angela Nieckele e Bruno Alvares de Azevedo
Área de Concentração: Petróleo e Energia
Data: 30/08/2017
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.32320
Resumo: Transcatheter Aortic Valve Replacement (TAVR) has become a powerful alternative for patients with aortic stenosis and a high surgical risk to face a traditional open chest surgery. The knowledge of the pressure distribution as well as shear stress at the aortic wall may help identify critical regions, where aortic remodeling process may occur. The purpose of the present work is to evaluate numerically the influence of the positioning of the prosthetic valve orifice in the flow field. The study was carried out on the basis of a particular patient who had undergone a TAVR. A 3D model was generated from computed tomography angiography and image segmentation of the aorta. Experimental data previously obtained in the same geometry indicated that the jet flow through the inlet valve is turbulent flow. The flow field was numerically determined with the commercial software Fluent. The turbulence was modeled with the two-equation k- SST model. To represent a pulsatile flow, different mass flow rates were imposed at the inlet valve. Similar flow pattern was observed for all flow rates investigated. It was shown that small variations of the tilt angle can modify the nature of the flow, displacing the position of the vortices and altering the location of high shear stress, as well as high pressure, at the aortic inner wall. It was also shown that an increase of the turbulent intensity at the entrance decreases the values of shear stress and pressure on the walls. These hemodynamic features may be relevant in the aortic remodeling process and the mechanical stresses may influence the durability of the valve prosthesis.