Multiphase simulation of blood flow within main thoracic arteries of 8-year-old child with coarctation of the aorta

Abstract

In the research, a numerical Computational Fluid Dynamics (CFD) model of the pulsatile blood flow was created and analysed. A real geometry of aorta and its thoracic branches of an 8-year old patient diagnosed with a congenital heart defect -coarctation of the aorta was used. The inlet boundary condition was implemented as the User Define Function according to measured values of volumetric blood flow. The blood flow was treated as multiphase using Euler-Euler approach. Plasma was set as the primary and dominant fluid phase, with the volume fraction of 0.585. The morphological elements (RBC and WBC) were set as dispersed phases being the remaining volume fraction.

Non-invasive diagnostics of blockage growth in the descending aorta-computational approach

“…ANSYS® 2020R2 includes a skewness measure, and this was evaluated in the present model, which had skewness measures from 0.71 to 0.77, which were within the acceptable range [5]. Furthermore, the chosen mesh had an acceptable numerical measure for moving meshing nodes and the convergences, in accordance with the literature [1,4,12]. The iteration maximum was set to achieve a reduction of relative and absolute residence times to reach convergence.…”

“…1 The process of converting 2D images to 3D aorta model using Materialize Mimics and SpaceClaim® 2020R2, also showing the dimensions for the inlet and four outlets of the aorta Fig. 2 The healthy model and four unhealthy models with descending blockages (25%, 35%, 50% and 65% stenosis) Based on the mesh values for the control model, we have set the number of elements as shown in Table 2 for the four unhealthy models with increasing degrees of blockage and checked the skewness values to ensure they are in the acceptable range within the literature [1,4,12].…”

“…In recent years, advances in computational modelling techniques enabled biomedical researchers' insight into the cardiovascular system using these techniques such as computational fluid dynamics (CFD) which facilitates investigation of various cardiovascular diseases including atherosclerosis and aneurysm. Several studies assumed different rheological properties to simulate the blood models numerically [1][2][3][4][5]. For example, blood can be simulated assuming Newtonian properties for large arteries and non-Newtonian properties for small arteries.…”

“…Typically, these studies present a patientspecific case to investigate the rheological properties and hemodynamic parameters for the blood flow in transient analysis. Other studies used CFD to examine the wall shear stress (WSS) and pressure (P) distribution for patients with aneurysms in various regions of the aorta [1][2][3][4][5]. They found that the arteries must be investigated in conjunction with the shear stress parameters such as the time-averaged wall shear stress (TAWSS) and the oscillation shear index (OSI).…”

Comparison between Single-Phase Flow Simulation and Multiphase Flow Simulation of Patient-Specific Total Cavopulmonary Connection Structures Assisted by a Rotationally Symmetric Blood Pump

“…The widely used single-phase flow simulation cannot simulate the mechanical behavior of RBCs. In recent studies, multiphase flow theory has been applied in more fields of hemodynamics [15][16][17][18]. Jung et al [8] used Euler-Euler method to simulate the multiphase flow of blood cells (red blood cells, white blood cells and platelets) and plasma and analyzed the mechanical behavior of blood cells.…”