3 research outputs found
A Reduced Order Model formulation for left atrium flow: an Atrial Fibrillation case
A data-driven Reduced Order Model (ROM) based on a Proper Orthogonal
Decomposition - Radial Basis Function (POD-RBF) approach is adopted in this
paper for the analysis of blood flow dynamics in a patient-specific case of
Atrial Fibrillation (AF). The Full Order Model (FOM) is represented by
incompressible Navier-Stokes equations, discretized with a Finite Volume (FV)
approach. Both the Newtonian and the Casson's constitutive laws are employed.
The aim is to build a computational tool able to efficiently and accurately
reconstruct the patterns of relevant hemodynamics indices related to the stasis
of the blood in a physical parametrization framework including the cardiac
output in the Newtonian case and also the plasma viscosity and the hematocrit
in the non-Newtonian one. Many FOM-ROM comparisons are shown to analyze the
performance of our approach as regards errors and computational speed-up.Comment: 21 pages, 14 figure
Data-Driven Reduced Order Modelling for Patient-Specific Hemodynamics of Coronary Artery Bypass Grafts with Physical and Geometrical Parameters
In this work the development of a machine learning-based Reduced Order Model (ROM)
for the investigation of hemodynamics in a patient-specific configuration of Coronary Artery
Bypass Graft (CABG) is proposed. The computational domain is referred to left branches
of coronary arteries when a stenosis of the Left Main Coronary Artery (LMCA) occurs.
The method extracts a reduced basis space from a collection of high-fidelity solutions via a
Proper Orthogonal Decomposition (POD) algorithm and employs Artificial Neural Networks
(ANNs) for the computation of the modal coefficients. The Full Order Model (FOM) is
represented by the incompressible Navier-Stokes equations discretized using a Finite Volume
(FV) technique. Both physical and geometrical parametrization are taken into account, the
former one related to the inlet flow rate and the latter one related to the stenosis severity.
With respect to the previous works focused on the development of a ROM framework for
the evaluation of coronary artery disease, the novelties of our study include the use of the
FV method in a patient-specific configuration, the use of a data-driven ROM technique and
the mesh deformation strategy based on a Free Form Deformation (FFD) technique. The
performance of our ROM approach is analyzed in terms of the error between full order and
reduced order solutions as well as the speed-up achieved at the online stage
Una mente sociale. Contributi in ricordo di Barbara Pojaghi
Il percorso prende le mosse negli anni '70, periodo di espansione delle tematiche psico-sociali in Italia, per approdare al più recente dibattito sulla comunicazione politica, sulle questioni di genere, sulla scuola come comunità che educa e sulla formazione nei luoghi di lavor