Author/Authors :
Gudarzi، Mohammad نويسنده School of Mechanical Engineering, Damavand Branch, Islamic Azad University, Damavand, Tehran, Iran , , Zamanian، Hashem نويسنده School of Mechanical Engineering, Damavand Branch, Islamic Azad University, Damavand, Tehran, Iran , , Oveisi، Atta نويسنده School of Mechanical Engineering, Iran University of Science and Technology ,
Abstract :
From about 280000 valve substitutes are now implanted worldwide each year, approximately half are mechanical valves. Mechanical heart valves designs include caged-ball, tilting-disc and bileaflet. Flow dynamics of blood around the valves are the most important part of design of valves. Today bileaflet valves are the most frequently implanted mechanical prosthesis. These valves are subject to malfunction in one or both of the valve leaflets. Although the occurrence of such malfunctions is low, they are life-threatening events that require emergency surgery. In this paper, we performed numerical simulations of the flow through a defective mechanical valve under several malfunction severity conditions. Our results show that the flow properties around and downstream of the defective valve is influenced by malfunction severity. Our results show that jet flow in velocity field, turbulent intensity and Reynolds stress has more impact on platelet activation than vorticity formation. Then we saw that the pressure decreasing and cavitation phenomena would not happen in these defective cases.
