NUMERICAL STUDY AND DYNAMIC BEHAVIOR ANALYSIS OF MECHANICAL HEART VALVE

This paper develops an analysis tool, for the mechanical heart valve designs, which contains a quick flow analysis model and a pseudo steady-state dynamic model. The flow model utilizes an irrotational, inviscid algorithm of source/doublet elements simulating the closed leaflet geometry and the aortic root coupled with a boundary layer model to simulate the viscous components. The numerical study provides quick simulation and vital design data of the shear stress distributed over the valve leaflet, the separation point prediction behind the leaflet and the sewing ring, and the aerodynamic loads acting on the leaflet. Those aerodynamic loads have been sent to a dynamic model, which simulates the leaflet motion as a 2nd order rotating system, to simulate the opening/closing characteristics of the leaflet. The analysis of the presented new heart valve design leads to a conclusion that the regurgitant volumes depends very much on the orientation of the gravity force. The maximum difference of the ratio of the valve closing regurgitation to the main flow can be as high as 12%. Hence the leaflet ought to be designed with a light material to avoid the unstable influence on the heart work due to the human's physical actions.