Analysis Of The Effect Of Leaflet OpeningAngle On Fluid Flow Past A BileafletMechanical Heart Valve

A 2-D laminar, steady state, Newtonian finite element CFD model was used to investigate the effect of leaflet opening angle on the flow through bileaflet heart valves. The numerical model was verified using LDV. Results of the study showed two different flow fields for the various opening angles; with the 78* leaflet opening angle the outer jet impinged on the aorta before rejoining the central jet downstream of the valve. For opening angles of 81° and above the outer jet recombined with the central jet without impinging on the aorta and the point of recombination was closer to the valve than that with the lower opening angle. As the opening angle of the leaflets increased the volumetric flow through the central orifice, the maximum velocity in the outer jet and the laminar shear stresses increased. The volumetric flow through the outer orifice, the maximum velocity through the central orifice and the area of the recirculation zone downstream of the valve leaflet decreased for an increase in opening angle. This study suggests that bileaflet heart valves with opening angles greater than 80" are preferable.