Mechanical Energy Losses Resulting from Stenosis of Semilunar Valves

Abstract

The reduced area for flow in a stenosed valve results in high blood velocities and correspondingly high kinetic energy. As fluid leaves the valve it encounters a sudden expansion in area, a jet is formed and the high shear at the jet surface results in rapid entrainment of surrounding fluid and turbulent mixing occurs. Because the flow is bounded by an arterial wall (for each of the semilunar valves) a recirculation region is established at the end of which the flow re-attaches to the wall. The resulting energy losses both within and downstream of the valve may be a large fraction of the work output from the ventricle driving the flow.