1. Multiscale Thermofluid Engineering Laboratory 1 Oxygen Transport in Blood Flows Past Staggered Fiber Arrays: A Computational Fluid Dynamics Study of an Oxygenator in Artificial Lung Yu-Chen Hsu & Kuang C. Lin Department of Mechanical and Electromechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan

2. Multiscale Thermofluid Engineering Laboratory 2 Kaohsiung National Sun Yat-Sen University

3. Multiscale Thermofluid Engineering Laboratory 3 PROCESS DESCRIPTION PRESENT

4. Multiscale Thermofluid Engineering Laboratory 4 PROCESS DESCRIPTION 1 2 3 4 BACKGROUND COMPUTER MODEL GOVERNING EQUATIONS ANALYSIS and CONCLUSIONS

5. Multiscale Thermofluid Engineering Laboratory 5 B BACKGROUND

6. Multiscale Thermofluid Engineering Laboratory 6 BACKGROUND Simple description Extracorporeal Membrane Oxygenation

7. Multiscale Thermofluid Engineering Laboratory 7 BACKGROUND H1N1 virus 1.Acute Lung Injury (ALI) 2.Acute Respiratory Distress Syndrome (ARDS) Cardiopulmonary diagram

8. Multiscale Thermofluid Engineering Laboratory 8 M. Ertan Taskin et al “Micro-scale modeling of flow and oxygen transfer in hollow-fiber membrane bundle” Journal of Membrane Science (2010) BACKGROUND Reference

9. Multiscale Thermofluid Engineering Laboratory 9 Fig. Comparison of the mini-oxygenator model predicted and benchmark device measured SO2 and m˙ O2 profiles along the fiber region. BACKGROUND Reference Consideration of pulsating flow (mimicking heart pumping) in this benchmark device.

10. Multiscale Thermofluid Engineering Laboratory 10 C COMPUTER MODEL

11. Multiscale Thermofluid Engineering Laboratory 11 COMPUTER MODEL Outlet – pressure outlet Wall – stationary and no slip wall Fig. Schematic of the computational domain

12. Multiscale Thermofluid Engineering Laboratory 12 Inlet Boundary Conditions COMPUTER MODEL 1. 2. 3.

13. Multiscale Thermofluid Engineering Laboratory 13 Inlet Boundary Conditions COMPUTER MODEL ECMO Reynolds numberWomersley parameters 1. 2. 3. Amplitude of blood flow

14. Multiscale Thermofluid Engineering Laboratory 14 COMPUTER MODEL

15. Multiscale Thermofluid Engineering Laboratory 15 Fiber Region COMPUTER MODEL 83 Fibers Fig. zoom-in view of the fiber bundle

16. Multiscale Thermofluid Engineering Laboratory 16 G GOVERNING EQUATIONS

17. Multiscale Thermofluid Engineering Laboratory 17 GOVERNING EQUATIONS Continuity equation Momentum equation Convection-diffusion equation

18. Multiscale Thermofluid Engineering Laboratory 18 Non-Newtonian-Power-Law model Non-Newtonian fluid (shear-thickening) Newtonian fluid Non-Newtonian fluid (shear-thinning) N.S.K. Chaitanya et al International Journal of Heat and Mass Transfer (2012) GOVERNING EQUATIONS

19. Multiscale Thermofluid Engineering Laboratory 19 Diffusion coefficient The oxygen binding capacity per volume of blood in STP assumption (0.167 ml Hb/ml) GOVERNING EQUATIONS

20. Multiscale Thermofluid Engineering Laboratory 20 A ANALYSIS

21. Multiscale Thermofluid Engineering Laboratory 21 Relative deviation (RD) ANALYSIS Parameters

22. Multiscale Thermofluid Engineering Laboratory 22 ANALYSIS Position L = 0 L = 1

23. Multiscale Thermofluid Engineering Laboratory 23 ANALYSIS M. Ertan Taskin et al Journal of Membrane Science (2010)

24. Multiscale Thermofluid Engineering Laboratory 24 ANALYSIS M. Ertan Taskin et al Journal of Membrane Science (2010)

25. Multiscale Thermofluid Engineering Laboratory 25 ANALYSIS Position 26D Location of where PO2 is analyzed

26. Multiscale Thermofluid Engineering Laboratory 26 ANALYSIS M. Ertan Taskin et al Journal of Membrane Science (2010) overpredict

27. Multiscale Thermofluid Engineering Laboratory 27 C CONCLUSIONS

28. Multiscale Thermofluid Engineering Laboratory 28 CONCLUSIONS STEADY vs UNSTEADY First R elative deviation around 0% - 13%. The maximum of r elative deviation is located at fist layer of fibers.

29. Multiscale Thermofluid Engineering Laboratory 29 CONCLUSIONS Amplitude Influence Second As the Reynolds number increases, the influence of the flow amplitude on oxygen transport is pronounced. This phenomenon explains why a heart beats vigorously when human body is in a deoxygenated situation. The effect of Reynolds number is minor whereas the amplitude effect on oxygen transport is the significant.

30. Multiscale Thermofluid Engineering Laboratory Consideration of pulsating blood flows in oxygen transport of artificial lung is necessary especially in greater Reynolds number. 30 CONCLUSIONS Take-home message

31. Multiscale Thermofluid Engineering Laboratory 31 CONCLUSIONS Take-home message Although oxygen transport in blood flows is mitigated at high heart beating rates, an increase of flow amplitude is able to compensate insufficient oxygen concentrations in blood flows.

32. Multiscale Thermofluid Engineering Laboratory 32