0
Research Papers

Pulsatile Flow and Oxygen Transport Past Cylindrical Fiber Arrays for an Artificial Lung: Computational and Experimental Studies

[+] Author and Article Information
Jennifer R. Zierenberg, Hideki Fujioka

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2099

Keith E. Cook

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2099; Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-2099

James B. Grotberg1

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2099grotberg@umich.edu

1

Corresponding author.

J Biomech Eng 130(3), 031019 (May 09, 2008) (12 pages) doi:10.1115/1.2907752 History: Received January 18, 2007; Revised December 06, 2007; Published May 09, 2008

The influence of time-dependent flows on oxygen transport from hollow fibers was computationally and experimentally investigated. The fluid average pressure drop, a measure of resistance, and the work required by the heart to drive fluid past the hollow fibers were also computationally explored. This study has particular relevance to the development of an artificial lung, which is perfused by blood leaving the right ventricle and in some cases passing through a compliance chamber before entering the device. Computational studies modeled the fiber bundle using cylindrical fiber arrays arranged in in-line and staggered rectangular configurations. The flow leaving the compliance chamber was modeled as dampened pulsatile and consisted of a sinusoidal perturbation superimposed on a steady flow. The right ventricular flow was modeled to depict the period of rapid flow acceleration and then deceleration during systole followed by zero flow during diastole. Experimental studies examined oxygen transfer across a fiber bundle with either steady, dampened pulsatile, or right ventricular flow. It was observed that the dampened pulsatile flow yielded similar oxygen transport efficiency to the steady flow, while the right ventricular flow resulted in smaller oxygen transport efficiency, with the decrease increasing with Re. Both computations and experiments yielded qualitatively similar results. In the computational modeling, the average pressure drop was similar for steady and dampened pulsatile flows and larger for right ventricular flow while the pump work required of the heart was greatest for right ventricular flow followed by dampened pulsatile flow and then steady flow. In conclusion, dampening the artificial lung inlet flow would be expected to maximize oxygen transport, minimize work, and thus improve performance.

Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Functional forms of velocity profiles considered: steady, pulsatile (mimicking flow from the right ventricle after passing through a compliance chamber), and right ventricular (mimicking flow leaving the right ventricle)

Grahic Jump Location
Figure 2

Schematic of unit cell and its appropriate boundary conditions for (a) in-line rectangular array and (b) staggered rectangular array

Grahic Jump Location
Figure 3

Top view of apparatus schematic

Grahic Jump Location
Figure 4

(a) End view of fiber bundle showing placement of spacers in between adjacent layer (b) overall fiber bundle available for gas exchange (excludes potted ends) with height (H), width (W), and length (L). The fluid flow is indicated by the dashed arrow.

Grahic Jump Location
Figure 5

Schematic of experimental circuit

Grahic Jump Location
Figure 6

Experimental steady, dampened pulsatile (right ventricular with compliance) and right ventricular flow rates at the inlet of the apparatus. The mean flow rate was 1043ml∕min corresponding to Re=5.

Grahic Jump Location
Figure 10

Streamline and concentration fields for right ventricular flow past a staggered array with Re=10: (a) t=3π∕10 and (b) t=7π∕4. (Note that the figure domain is between the 18th and 19th fibers.)

Grahic Jump Location
Figure 11

Computational Sherwood number, Sh̿, for steady, pulsatile, and right ventricular flows with fibers arranged in the in-line and staggered configurations

Grahic Jump Location
Figure 12

Computational instantaneous surface averaged Sherwood numbers, Sh¯, for Re=10 shown for steady, pulsatile, and right ventricular flows with fibers arranged in the in-line and staggered configurations

Grahic Jump Location
Figure 13

Time-averaged pressure drop across a unit cell, ΔP∕Lx̿, for steady, pulsatile, and right ventricular flows with fibers arranged in the in-line and staggered configurations

Grahic Jump Location
Figure 14

Instantaneous pressure drop across a unit cell, ΔP∕Lx, for Re=10 shown for steady, pulsatile, and right ventricular flows with fibers arranged in the in-line and staggered configurations

Grahic Jump Location
Figure 15

Average work required to drive fluid across one unit cell, W, for steady, pulsatile, and right ventricular flows with fibers arranged in the in-line and staggered configurations

Grahic Jump Location
Figure 16

Experimental Sherwood number, Sh̿, for steady, pulsatile, and right ventricular flows. The experimental fiber bundle best corresponds to the computationally investigated staggered array.

Grahic Jump Location
Figure 8

Streamline and concentration fields for pulsatile flow past a staggered array with Re=10: (a) t=π∕2 and (b) t=3π∕2. (Note that the figure domain is between the 18th and 19th fibers.)

Grahic Jump Location
Figure 9

Streamline and concentration fields for right ventricular flow past an in-line array with Re=10: (a) t=3π∕10 and (b) t=7π∕4. (Note that the figure domain is between the 18th and 19th fibers.)

Grahic Jump Location
Figure 7

Streamline and concentration fields for pulsatile flow past an in-line array with Re=10: (a) t=π∕2 and (b) t=3π∕2. (Note that the figure domain is between the 18th and 19th fibers.)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In