An Investigation on the Aggregation and Rheodynamics of Human Red Blood Cells Using High Performance Computations

Abstract

Studies on the haemodynamics of human circulation are clinically and scientifically important. In order to investigate the effect of deformation and aggregation of red blood cells (RBCs) in blood flow, a computational technique has been developed by coupling the interaction between the fluid and the deformable RBCs. Parallelization was carried out for the coupled code and a high speedup was achieved based on a spatial decomposition. In order to verify the code's capability of simulating RBC deformation and transport, simulations were carried out for a spherical capsule in a microchannel and multiple RBC transport in a Poiseuille flow. RBC transport in a confined tube was also carried out to simulate the peristaltic effects of microvessels. Relatively large-scale simulations were carried out of the motion of 49,512 RBCs in shear flows, which yielded a hematocrit of 45%. The large-scale feature of the simulation has enabled a macroscale verification and investigation of the overall characteristics of RBC aggregations to be carried out. The results are in excellent agreement with experimental studies and, more specifically, both the experimental and simulation results show uniform RBC distributions under high shear rates (60–100/s) whereas large aggregations were observed under a lower shear rate of 10/s.

Fluid–structure interaction of flexible submerged vegetation stems and kinetic turbine blades

“…As already noted, two types of FSI problems are investigated: submerged vegetation in a channel flow and kinetic turbine rotors. The FSI code has already been extensively verified in previous publications [10,[18][19][20][21][22][23], and thus, only verifications specific to the class of the investigated cases are shown followed by results of interest.…”

“…An IBM algorithm ties the two solvers together. This FSI methodology has already been successfully implemented for a range of problems from bio-fluids of red blood cells flow [18,19] and urine flow in the ureter [20] to sediment [21,22] and marine tidal turbines [10]. In this section, the main points of the method are highlighted, where further details are given in Refs.…”

Numerical Study on Concrete Pumping Behavior via Local Flow Simulation with Discrete Element Method

“…The fluid phase represents the mortar and the particle suspension models the aggregates; the flow of mortar is mainly simulated according to CFD and the motion of discrete particles is tracked, with or without further considering the interactions between particles (see, e.g., [33,34,35,36,37]). This way of treating multi-phase material has been also considered in many other topics where the interaction between different phases is significant (see, e.g., the research on gas–solid separation [38], on blood flow [39,40], on fracturing solids [41], etc.) Nevertheless, considering the volume fraction of solid phase in fresh concrete, the accuracy of these methods should be further investigated, since the aggregate packing feature strongly influences the rheological properties of suspension [42].…”

Digital blood in massively parallel CPU/GPU systems for the study of platelet transport

“…Similarly, the lattice Boltzmann flow solver could be replaced by another option, which however needs to be similarly parallelizable through domain decomposition and allow interaction with solid particles through an immersed boundary method. In the last decade, many groups have been working on HPC-capable cellular blood flow tools [13,[19][20][21][22][23] dealing with problems of increased complexity, which do however not reach the goal of a computational framework that fulfils simultaneously all the above-mentioned criteria.…”