Investigation of unsteady flow in a model of a ventricular assist device by numerical modelling and comparison with experiment.

摘要: Abstract Prior to this study, a clinical prototype of sac-type ventricular assist device (VAD) was investigated experimentally, using both flow visualisation and Laser Doppler anemometry (LDA), in order optimise its geometry. As poor optical access precluded the experimental investigation some areas VAD, computational fluid dynamics (CFD) used present work. Flow patterns during one full pumping cycle were simplified model VAD. The numerical solutions compared with results from an identical physical model. consists hemispherical cylinder two attached tubes for inflow outflow. Instead diaphragm device, which deforms non-uniformly pumping, piston matching crown used. A finite volume method employed solve governing equations three-dimensional, unsteady, laminar incompressible, Newtonian fluid. general features predicted very well by simulation, differences details structures. This allows conclusion that CFD can be facilitate improvement design device. comparison one-component velocity time histories at selected points showed velocities approximately 20–50% lower than those measured LDA. Such underprediction would lead erroneous particle residence times may result underestimation wall shear stresses.