Pulsatile blood flow and gas exchange across a cylindrical fiber array

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Gas Transport

Background:

• Understanding blood flow dynamics and gas exchange in microvasculature is crucial for physiological and medical applications.
• Microfluidic devices are increasingly used to model biological processes, requiring accurate simulations of fluid behavior.

Purpose of the Study:

• To numerically simulate pulsatile blood flow and gas transport (oxygen and carbon dioxide) through a cylindrical microfiber array.
• To investigate the influence of flow pulsatility and blood flow field on gas exchange efficiency.
• To evaluate the risk of thrombosis by analyzing shear stress within the microfibers.

Main Methods:

• Blood modeled as a homogeneous Casson fluid.
• Hemoglobin equilibrium with oxygen and carbon dioxide assumed.
• Numerical simulation of pulsatile flow and gas transport.
• Calculation of Sherwood number and local shear stress.

Main Results:

• Flow pulsatility significantly enhances gas transport and exchange.
• Gas exchange efficiency is sensitive to the blood flow field across microfibers.
• A linear relationship between Sherwood number and Reynolds number was observed, aligning with experimental data.
• Increased gas transport often correlates with higher flow resistance.
• Computed shear stress remained below the thrombosis threshold in all simulated cases.

Conclusions:

• Pulsatile blood flow is an effective mechanism for enhancing gas transport in microfluidic systems.
• The study provides insights into the complex interplay between flow dynamics, gas exchange, and thrombosis risk in microengineered environments.
• Numerical simulations offer a valuable tool for optimizing microfluidic designs for improved physiological function.