Hemodynamic analysis of aortic bileaflet mechanical heart valve under different physiologic conditions
The velocity distribution,vortex evolution,viscous shear stress distribution and Reynolds shear stress distribution downstream of the aortic bileaflet mechanical heart valve are investigated under different physiological conditions using computational fluid dynamics method.At peak systole,the blood jet is more intense in the exercise state than in the other two states,with a maximum blood flow rate of 2.1 m/s.The analysis on vortex evolution shows that the shear layer is the obvious flow feature in the 3 physiological states and that the blood interacts more strongly with the aortic sinus at peak systole.For viscous shear stress,when the valve leaflets are fully open,the leaflets impede blood flow across the valve in the valvular region.The interaction between the blood flow and the valve leaflets results in high shear stress,and the maximum viscous shear stress observed in the 3 physiologic states is less than 8 N/m2.The maximum Reynolds shear stress observed in the 3 physiologic states is 700 N/m2.The study provides a theoretical basis for surgical valve selection and postoperative rehabilitation.