TY - JOUR
T1 - CRRT circuit venous air chamber design and intra-chamber flow dynamics
T2 - a computational fluid dynamics study
AU - Shimizu, Kota
AU - Yamada, Toru
AU - Moriyama, Kazuhiro
AU - Kato, China
AU - Kuriyama, Naohide
AU - Hara, Yoshitaka
AU - Kawaji, Takahiro
AU - Komatsu, Satoshi
AU - Morinishi, Yohei
AU - Nishida, Osamu
AU - Nakamura, Tomoyuki
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/12
Y1 - 2024/12
N2 - Background: Venous air trap chamber designs vary considerably to suit specific continuous renal replacement therapy circuits, with key variables including inflow design and filter presence. Nevertheless, intrachamber flow irregularities do occur and can promote blood coagulation. Therefore, this study employed computational fluid dynamics (CFD) simulations to better understand how venous air trap chamber designs affect flow. Methods: The flow within a venous air trap chamber was analyzed through numerical calculations based on CFD, utilizing large eddy simulation. The working fluid was a 33% glycerin solution, and the flow rate was set at 150 ml/min. A model of a venous air trap chamber with a volume of 15 ml served as the computational domain. Calculations were performed for four conditions: horizontal inflow with and without a filter, and vertical inflow with and without a filter. Streamline plots and velocity contour plots were generated to visualize the flow. Results: In the horizontal inflow chamber, irrespective of filter presence, ultimately the working fluid exhibited a downstream vortex flow along the chamber walls, dissipating as it progressed, and being faster near the walls than in the chamber center. In the presence of a filter, the working fluid flowed uniformly toward the outlet, while in the absence of a filter the flow became turbulent before reaching the outlet. These observations indicate a streamlining effect of the filter. In the vertical inflow chamber, irrespective of filter presence, the working fluid flowed vertically from the inlet into the main flow direction. Part of the working fluid bounced back at the chamber bottom, underwent upward and downward movements, and eventually flowed out through the outlet. Stagnation was observed at the top of the chamber. Without a filter, more working fluid bounced back from the bottom of the chamber. Conclusions: CFD analysis estimated that the flow in a venous air trap chamber is affected by inflow method and filter presence. The “horizontal inflow chamber with filter” was identified as the design creating a smooth and uninterrupted flow throughout the chamber.
AB - Background: Venous air trap chamber designs vary considerably to suit specific continuous renal replacement therapy circuits, with key variables including inflow design and filter presence. Nevertheless, intrachamber flow irregularities do occur and can promote blood coagulation. Therefore, this study employed computational fluid dynamics (CFD) simulations to better understand how venous air trap chamber designs affect flow. Methods: The flow within a venous air trap chamber was analyzed through numerical calculations based on CFD, utilizing large eddy simulation. The working fluid was a 33% glycerin solution, and the flow rate was set at 150 ml/min. A model of a venous air trap chamber with a volume of 15 ml served as the computational domain. Calculations were performed for four conditions: horizontal inflow with and without a filter, and vertical inflow with and without a filter. Streamline plots and velocity contour plots were generated to visualize the flow. Results: In the horizontal inflow chamber, irrespective of filter presence, ultimately the working fluid exhibited a downstream vortex flow along the chamber walls, dissipating as it progressed, and being faster near the walls than in the chamber center. In the presence of a filter, the working fluid flowed uniformly toward the outlet, while in the absence of a filter the flow became turbulent before reaching the outlet. These observations indicate a streamlining effect of the filter. In the vertical inflow chamber, irrespective of filter presence, the working fluid flowed vertically from the inlet into the main flow direction. Part of the working fluid bounced back at the chamber bottom, underwent upward and downward movements, and eventually flowed out through the outlet. Stagnation was observed at the top of the chamber. Without a filter, more working fluid bounced back from the bottom of the chamber. Conclusions: CFD analysis estimated that the flow in a venous air trap chamber is affected by inflow method and filter presence. The “horizontal inflow chamber with filter” was identified as the design creating a smooth and uninterrupted flow throughout the chamber.
KW - Computational fluid dynamics
KW - Computational fluid dynamics analysis
KW - Continuous renal replacement therapy
KW - Grid diagram
KW - Horizontal inflow chamber
KW - Streamlines of the flow field
KW - Velocity contours of the flow field
KW - Venous air trap chamber
KW - Vertical inflow chamber
KW - Working fluid
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U2 - 10.1186/s41100-024-00569-5
DO - 10.1186/s41100-024-00569-5
M3 - Article
AN - SCOPUS:85203816898
SN - 2059-1381
VL - 10
JO - Renal Replacement Therapy
JF - Renal Replacement Therapy
IS - 1
M1 - 54
ER -