Abstracts: ASAIO Bioengineering/tissue Engineering Abstracts
TRANSIENT FLOW NUMERCIAL SIMULATION OF AN AXIAL FLOW PEDIATRIC VAD FOR INFANTS AND CHILDREN
Thousands of infants and children will benefit from the longer-term bridge-to-transplant capabilities of pediatric VADs (PVADs). Since few mechanical support options are available in the US, we have designed and optimized an axial flow PVAD with an impeller that is fully suspended by magnetic bearings. Computational fluid dynamics (CFD) has been employed during design iterations and multiple optimizations of this VAD. This CFD study explores transient flow phenomena in the pump.
Three types of transient simulations (TS) were completed to mimic physiological flows: 1) pulsed inlet pressure or a time-varying boundary condition (TVBC), 2) rotating-stationary component dynamics to capture the blade passage frequency or transient rotational sliding interfaces (TRSI), and 3) a combination of TVBC and TRSI to simulate the most realistic implant conditions. For each TS, the pressure rise and fluid forces (axial and radial) were estimated for the final magnetic suspension / motor design.
The TS demonstrated the dependence of the radial fluid forces on the diffuser region and inflow conditions. Maximum radial fluid forces during TRSI runs were found to be approximately 0.09 N. For TVBC runs, the pressure rise and fluid forces were determined to be sensitive to the tim.
These transient simulations illustrated the PVAD’s response to dynamic flow conditions, which are realistic when considering in vivo implant scenarios.Copyright © 2005 by the American Society for Artificial Internal Organs