Three-dimensional numerical simulation of flow in a bileaflet heart valve using overset grids

Abstract

This chapter presents three-dimensional, laminar, unsteady solutions for the flow through bileaflet mechanical heart valves under steady flow conditions. The computed flow fields show that the flow is unsteady and asymmetric at a Reynolds number of 750. These results confirm the need for fully 3D simulations for this complex flow. To present the condition the chapter uses a geometric model of a bileaflet MHV as a prosthetic for the aortic heart valve. The primary simplification made in geometric model is that the aortic root contains a single axi-symmetric sinus and not three aortic sinuses. The bileaflets in the model MHV closely resemble the St. Jude Medical (SJM) Standard valve. To simulate this complex geometrical configuration, domain-decomposition method with structured overset (Chimera) grids is used. The method does not require one-to-one matching of grid lines across sub-domain interfaces, thus, permitting a great deal of flexibility. The primary conclusion is that physically realistic simulations of MHV flows require three-dimensional simulations with no assumptions about the symmetry of the flow.