ETD

• Direct Numerical Simulation
• Immersed boundary method.
• Windkessel

In cardiovascular research windkessel refers to a simplified model used to mimic the impedance of arteries and vessels. In the context of three-dimensional (3D) numerical simulations, the windkessel model is parameterized as a 0D system and the resulting system of ordinary differential equations is used as a boundary condition to a subset of the cardiovascular system. However connecting this lower dimensional model to the 3D simulation is ill posed, since the coupling relies in assuming the velocity and/or pressure distribution at the inlets/outlets of the 3D system.
As an attempt to overcome the above mentioned issues, this master’s thesis proposes a full 3D numerical solution of a windkessel system, which can be applied as a 3D closed-loop condition in cardiovascular numerical simulations. The system is made of a cylindrical tube partially deformable, along with porous and flow acceleration regions, in order to account for the resistive, capacitive and inertial nature of the underlying vessels. The simulation employs a direct numerical simulation of the Navier Stokes Equations for the fluid flow, whereas immersed boundary method has been used to simulate the interaction between fluid and the immersed bodies.
The results, in terms of pressure and flow-rate, are consistent with physiological values and this model is promising to be incorporated in high-fidelity computational models of the human heart.