An experimental and numerical analysis was performed for the Wang-Zwische double-lumen cannula (DLC) (Avalon Elite). The aim of this work was to provide insight for future improvement by characterizing the fluid dynamic behavior of the novel catheter with metrics often associated with blood trauma. Pressure and flow distributions were measured on a steady-flow rig using a 50% glycerol-water mixture by im- posing a 2 L/min flow rate across the drainage and infusion lumens. The fluid was modeled as Newtonian with density of 1050 kg/m3 and dynamic viscosity of 0.0035 kg/ms. Reyn- olds numbers typical for transitional flow (Re 2000–2500) were computed within the lumens because of the changing cross-sections of the cannula geometry. Numerical computa- tions were performed using the steady three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations and the low-Reynolds k- turbulence model. Discretization of gov- erning equations was based on a cell-centered finite volume method. Numerical results correlated well with global per- formance of the cannula, allowing evaluation of the geometry toward potential blood trauma. Peak wall shear stress (WSS) in the drainage lumen was higher than that of infusion lumen, mainly due to the presence of side holes. Furthermore, recir- culation regions were predicted in transition tubing to con- nectors of both the drainage and the infusion lumens because of adverse pressure gradients caused by the sudden enlarge- ment of the cannula geometry. In this three-dimensional com- putational fluid dynamics (CFD) study, we observed higher peak WSS values for the drainage lumen, which may poten- tially cause blood trauma. Furthermore, recirculation regions were predicted in the proximity of the exit sections of both the infusion and drainage lumens, which may contribute to thrombosis formation. This study provides insight for future DLC modifications in minimizing cannula-induced blood trauma and thrombogenicity in long-term applications.
Numerical and experimental flow analisys of the Wang-Zwishe Double-lumen cannula
Fragomeni G;
2011-01-01
Abstract
An experimental and numerical analysis was performed for the Wang-Zwische double-lumen cannula (DLC) (Avalon Elite). The aim of this work was to provide insight for future improvement by characterizing the fluid dynamic behavior of the novel catheter with metrics often associated with blood trauma. Pressure and flow distributions were measured on a steady-flow rig using a 50% glycerol-water mixture by im- posing a 2 L/min flow rate across the drainage and infusion lumens. The fluid was modeled as Newtonian with density of 1050 kg/m3 and dynamic viscosity of 0.0035 kg/ms. Reyn- olds numbers typical for transitional flow (Re 2000–2500) were computed within the lumens because of the changing cross-sections of the cannula geometry. Numerical computa- tions were performed using the steady three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations and the low-Reynolds k- turbulence model. Discretization of gov- erning equations was based on a cell-centered finite volume method. Numerical results correlated well with global per- formance of the cannula, allowing evaluation of the geometry toward potential blood trauma. Peak wall shear stress (WSS) in the drainage lumen was higher than that of infusion lumen, mainly due to the presence of side holes. Furthermore, recir- culation regions were predicted in transition tubing to con- nectors of both the drainage and the infusion lumens because of adverse pressure gradients caused by the sudden enlarge- ment of the cannula geometry. In this three-dimensional com- putational fluid dynamics (CFD) study, we observed higher peak WSS values for the drainage lumen, which may poten- tially cause blood trauma. Furthermore, recirculation regions were predicted in the proximity of the exit sections of both the infusion and drainage lumens, which may contribute to thrombosis formation. This study provides insight for future DLC modifications in minimizing cannula-induced blood trauma and thrombogenicity in long-term applications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
