Paper Number
BB8 

Session
Biomaterials and Biofluid Dynamics

Title
Multiscale characterization of nanoparticle diffusion in cellular blood flow under shear

Presentation Date and Time
October 21, 2019 (Monday) 2:20

Track / Room
Track 6 / Room 306B

Authors (Click on name to view author profile)

1. Liu, Zixiang (Georgia Institute of Technology, The George W. Woodruff School of Mechanical Engineering)
2. Clausen, Jonathan R. (Sandia National Laboratories, Thermal and Fluid Processes)
3. Rao, Rekha R. (Sandia National Laboratories, Fluid and Reactive Processes)
4. Ku, David N. (Georgia Institute of Technology, The George W. Woodruff School of Mechanical Engineering)
5. Aidun, Cyrus K. (Georgia Institute of Technology, The George W. Woodruff School of Mechanical Engineering)

Author and Affiliation Lines (in printed abstract book)
Zixiang Liu¹, Jonathan R. Clausen², Rekha R. Rao³, David N. Ku¹, and Cyrus K. Aidun^1
1The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332; ²Thermal and Fluid Processes, Sandia National Laboratories, Alburqueque, NM 87185-0836; ³Fluid and Reactive Processes, Sandia National Laboratories, Albuquerque, NM 87185-0836

Speaker / Presenter 
Liu, Zixiang

Text of Abstract
Blood is a complex fluid of polydisperse particulate suspension that involve both nanoscale biomolecules and microscale cells. Characterizing the transport and rheology of such a complex fluid system requires spatial resolution at various scales. In this work, we apply a lattice-Boltzmann/Langevin-dynamics/spectrin-link (LB-LD-SL) multiscale method (Liu et al. Int. J. Numer. Methods Fluids 2019) to calculate the three-dimensional shear-induced diffusivity tensor of nanoscale particles (NP) in a sheared blood flow over a wide range of shear rate and hematocrit (Liu et al. J. Fluid Mech. 2019). The diagonal diffusivity terms show nonlinear dependence on shear rate, where the cross-stream terms exhibit sublinear scales ~O(γ^0.8) and the longitudinal diffusivity shows superlinear scales ~O(γ^k) (1≤k≤1.8). The hematocrit dependence is found to be mostly linear ~O(φ) except at high hematocrits, where the longitudinal term scales quadratically ~O(φ²) while the vorticity term varies sublinearly ~O(φ^0.6). The nonlinear scales are found to be associated with the hemorheology-dependent alteration of the microstructure and red blood cell morphology. Based on the scaling observations, a constitutive law of the diffusivity tensor is proposed to bridge hemorheology and NP diffusive properties. The characterized NP diffusivity tensor provides an accurate constitutive relation for large-scale continuum modeling of NP biotransport applications. Extension of this computational method to applications in thrombosis will also be discussed.