The bileaflet mechanical heart valve is one of the most commonly used prosthetic heart valves. Major problem of this prosthetic heart valve is thrombosis and thromboembolism. Generally known causes of these phenomena are the shear stress and separation of flow around the valve. Computation fluid dynamics(CFD) is a useful tool which can be used to investigate the flow downstream of heart valves and the complex flow patterns within the valve can also be identified.
In this thesis, two-dimensional incompressible Navier-Stokes equation is solved to analyze opening and closure of a prosthetic heart valve in the laminar blood flow. Hyperbolic-type incompressible governing equation is constructed with the pseudo-compressibility and dual time stepping. Basic finite difference method is adopted and the implicit Point-SGS scheme is used. To model the dynamic motion of the prosthetic heart valve, the conventional Chimera grid scheme is used in the time dependent manner with the new concept of dynamic domain dividing line(DDDL) installed for the narrow space between the bodies.
Calculated results are first compared with the existing experimental data and other numerical solutions to validate the present computer code. Then, the flow around the bileaflet heart valve opening and closing cyclically in the narrow blood vessel is solved. The inlet flow is first assumed uniform but a periodic flow is later developed in the artery by the repeated opening and closing of the bileaflet valve. The time-dependent shear stress distribution behind the valve and on the blood vessel is plotted.
