BloodSim: Coupled Solid-Fluid Simulation of Cardiovascular Systems
Cardiovascular systems typically feature strong interaction between solid and fluid phases. Software has been developed to couple ANSYS to CFX, via an external interface, to produce the capacity for simulation of systems of this type. The interface software passes pressure data from the fluid phase to the solid phase, which returns boundary position and velocity information. This process iterates until consistent results are obtained across the wetted boundary. There is facility for relaxation of pressure, displacement or both to assist convergence of the process. Automatic remeshing of the fluid domain is performed when the distorting mesh violates quality constraints. This feature is necessary for systems like heart valves that feature severe topological distortion. Results are presented for a series of applications including comparison with Womersley's analytical solutions for pulse transmission in an elastic-walled artery, analysis of the fluid and structural characteristics of a stented artery and simulations of the operation of an extracorporeal heart assist device.