Development of new simulation strategies to investigate aorta hemodynamics by integrating in-vivo data and RBF mesh morphing approach

This thesis aims to develop new numerical strategies to evaluate thoracic aorta hemodynamics in order to fill the gap between numerical simulations and clinical environment. Firstly, a novel framework to analyse hemodynamics in the ascending thoracic aortic aneurysm has been developed with the aim to investigate the effects of the bulge progression on the aorta fluid dynamics at different stages of enlargements. Radial Basis Functions (RBF) mesh morphing techniques have been used to drive the deformation of a statistical aortic healthy shape to a statistical pathological aortic shape. Computational fluid dynamics (CFD) simulations have been performed for selected incremental bulge configurations and the main hemodynamic indices have been analysed. The second activity concerned the development of a new numerical approach able to include the motion and deformation of ascending aorta during cardiac cycle in a transient CFD simulation. The developed approach is based on CT-gated images to obtain 3D aorta models at each phase of cardiac cycle and on RBF mesh morphing techniques to model the geometric changes of aorta. Standard CFD and 2-way FSI simulations have been also performed to carry out a comparison in terms of hemodynamic results and computational costs. Hemodynamic differences among different simulation strategies have been detected highlighting the not negligible influence of geometric modifications of ascending aorta during cardiac cycle and a significant increase in simulation speed has been obtained thanks to the new developed approach.