Computational fluid dynamics of ventricular ejection on the CRAY Y-MP

Computational fluid dynamics was used to model the effects of left ventricular geometry on intraventricular pressure gradients. The Navier-Stokes equations were solved on the CRAY Y-MP supercomputer using finite element analysis. The Fluid Dynamics Analysis Package (FIDAP) and custom made software simulated unsteady-ventricular ejection. A FORTRAN code was developed to process digitized ejection velocity data, left ventricular volume, long to short axis ratio, and aortic ring area, and to create FIDAP source files which model the ejecting chamber, including initial and boundary conditions representing wall velocities and accelerations. The model was used to simulate different left ventricular geometries under normal and pathologic conditions. Simulations showed that eccentric chamber shapes require higher pressure gradients than spherical, and convective acceleration effects are intensified with outflow orifice stenosis