Numerical Analysis Of Blood Flow Research Articles

Numerical analysis of blood flow in a branched modular stent-graft for aneurysms covering all zones of the aortic arch

Numerical analysis of blood flow in a branched modular stent-graft for aneurysms covering all zones of the aortic arch

Numerical Analysis of Blood Flow through Blood Vessels with Atherosclerosis Using the Newtonian Flow Model

Numerical Analysis of Blood Flow through Blood Vessels with Atherosclerosis Using the Newtonian Flow Model

Numerical analysis of blood flow in the abdominal aorta under simulated weightlessness and earth conditions

Blood flow through the abdominal aorta and iliac arteries is a crucial area of research in hemodynamics and cardiovascular diseases. To get in to the problem, this study presents detailed analyses of blood flow through the abdominal aorta, together with left and right iliac arteries, under Earth gravity and weightless conditions, both at the rest stage, and during physical activity. The analysis were conducted using ANSYS Fluent software. The results indicate, that there is significantly less variation in blood flow velocity under weightless conditions, compared to measurement taken under Earth Gravity conditions. Study presents, that the maximum and minimum blood flow velocities decrease and increase, respectively, under weightless conditions. Our model for the left iliac artery revealed higher blood flow velocities during the peak of the systolic phase (systole) and lower velocities during the early diastolic phase (diastole). Furthermore, we analyzed the shear stress of the vessel wall and the mean shear stress over time. Additionally, the distribution of oscillatory shear rate, commonly used in hemodynamic analyses, was examined to assess the effects of blood flow on the blood vessels. Countermeasures to mitigate the negative effects of weightlessness on astronauts health are discussed, including exercises performed on the equipment aboard the space station. These exercises aim to maintain optimal blood flow, prevent the formation of atherosclerotic plaques, and reduce the risk of cardiovascular complications.

Numerical analysis of blood flow through stenosed microvessels using a multi-phase model

Blood flow in arterioles have attracted considerable research attention due to their clinical implications. However, the fluid structure interaction between red blood cells and plasma in the blood poses formidable difficulty to the computational efforts. In this contribution, we seek to represent the red blood cells in the blood as a continuous non-Newtonian phase and construct a multi-phase model for the blood flow in microvessels. The methods are presented and validated using a channel with sudden expansion. And the resulting blood flow inside a stenosed microvessel is investigated at different inlet velocity amplitudes and hematocrits. It is show that the increase of both inlet velocity amplitude and inlet hematocrit leads to longer and thicker cell-rich layer downstream the stenosis. Besides, it is found that the maximum values of wall shear stress scales up with inlet velocity amplitudes and hematocrits. These results show the validity of the proposed computational model and provide helpful insights into blood flow behaviors inside stenosed vessels.

Numerical Approach for The Evaluation of Hemodynamic Behaviour in Peripheral Arterial Disease: A Systematic Review

Reduced blood flow to the lower extremities causes peripheral arterial disease (PAD), which is caused by atherosclerotic plaque in the arterial wall. If this impairment is not treated, it will result in severe vascular diseases like ulceration and gangrene. Previous research has shown that while evaluating the pathology of the peripheral artery, the assumption of the model geometry significantly impacts the uncertainty of the stenosis area. However, more work needs to be done to understand the interaction between mechanical better and flow conditions in the peripheral artery using a separate computer model of the cardiovascular system. This paper reviews the numerical approach on pre- and post-treatment of hemodynamic behavior in peripheral arterial disease (PAD). The goal of this study was to thoroughly examine the most recent developments with the application of computational studies in PAD from 2017 to 2022. While FSI investigation highlights the behavior of both the fluid and structure domains (blood and artery) during the numerical analysis of blood flow, CFD simulations primarily focus on the fluid domain (blood) behavior. Out of 92 research publications, 19 were appropriate for this assignment. This thorough study divides the publications into the categories of CFD, and FSI approaches. The results were then reviewed in accordance with the wall characteristic, analytical method, geometry, viscosity models, and validation. This paper summarizes the parameters of geometrical construction, viscosity models, analysis methods, and wall characteristics taken into consideration by the researchers to identify and simulate the blood flood flow in the stenosis area. These parameters are summarised in this study. Additionally, it could offer systematic data to help future studies produce better computational analyses.

Numerical solution of magnetohydrodynamics effects on a generalised power law fluid model of blood flow through a bifurcated artery with an overlapping shaped stenosis.

This paper presents a numerical analysis of blood flow in a diseased vessel within the presence of an external magnetic field. The blood flow was considered to be incompressible and fully developed, in that the non-Newtonian nature of the fluid was characterised as a generalised power law model for shear-thinning, Newtonian, and shear-thickening fluids. The impact of a transverse directed external magnetic field on blood flow through a stenosed bifurcated artery was investigated. The arterial geometry was considered as a bifurcated channel with overlapping shaped stenosis. The problem was treated mathematically using the Galerkin Least-Squares (GLS) method. The implementation of this numerical method managed to overcome the numerical instability faced by the classical Galerkin technique when adopted to a highly viscous flow. The benefit of GLS in circumventing the Ladyzhenskaya-Babuška-Brezzi (LBB) condition was utilized by evaluating both the velocity and pressure components at corner nodes of a unstructured triangular element. The non-linearity that emerged from the convective terms was then treated using the Newton-Raphson method, while the numerical integrals were computed using a Gaussian quadrature rule with six quadrature points. The findings obtained from this study were then compared with available results from the literature as well as Comsol multiphysics software to verify the accuracy and validity of the numerical algorithms. It was found that the application of magnetic field was able to overcome flow reversal by 39% for a shear-thinning fluid, 26% for a Newtonian fluid, and 27% for a shear-thickening fluid. The negative pressure and steep wall shear stress which occurs at the extremities of an overlapping stenosis throat were diminished by rise in magnetic intensity. This prevented thrombosis occurrence and produced a uniform calm flow.

A NUMERICAL INVESTIGATION OF BLOOD FLOW THROUGH THE AORTIC VALVE

This article aims to present a numerical analysis of blood flow in the aortic valve using fluid-structure interaction simulation. The finite element method is employed both for fluid and solid domains, and the monolithic scheme is used for the strong fluid-structure interaction coupling to solve well the two challenges: add-mass and large deformation problems. The Navier-Stokes equations are solved using the integrated method based on the unstructured grid on Arbitrary Lagrangian-Eulerian (ALE) framework with the total Lagrangian formulation is used for the non-linear behavior of the aortic valve. A smoothing technique based on the Laplace equation is employed to improve the mesh quality for both 2D and 3D geometries. The fluid characteristics, such as the velocity and pressure in the valve, are evaluated and analyzed in detail. The results show that velocity and pressure reach their maximum values when the valve is at its maximum opening. On the other hand, more vortices appear behind the valve during the closing phases. The simulation results can be used to help fully to predict and treat cardiovascular diseases.

Numerical analysis of blood flow in abdominal aortic aneurysm using finite volume method

There is a deadly cardiovascular disease that can cause swelling of the Abdominal Aorta. This disease is known as Abdominal Aortic Aneurysm (AAA). AAA is believed to be a degenerative process caused by genetic factors, gender, body weight, and age. Changes in collagen and elastin in the aortic wall are the cause of the degeneration process. Therefore, it will cause dilatation of the aortic wall. Swelling of the aortic blood vessels will affect the blood flow velocity in the aortic blood vessels. This research aims to analyze the velocity of blood flow in the Abdominal Aortic Aneurysm based on swelling diameter, proximal neck length, and aneurysm channel length using Computational Fluids Dynamics (CFD). The blood flow velocity was modeled using mathematical language based on mass continuity equations and momentum equations. Then the finite volume method was one method to solve the mathematical model. MATLAB and ANSYS FLUENT software were used to simulate the velocity of blood flow analysis. The results of the research were shown that the larger the diameter and swelling channel length, the smaller the velocity of blood flow produced. Then, the greater the length of the proximal neck, the faster the resulting blood flow will be.

Numerical Analysis of Blood Flow through COVID-19 Infected Arteries

Computational Fluid Dynamics has become relevant in the study of hemodynamics, where clinical results are challenging to obtain. This paper discusses a 2-Dimensional transient blood flow analysis through an arterial bifurcation for patients infected with the Coronavirus. The geometry considered is an arterial bifurcation with main stem diameter 3 mm and two outlets. The left outlet (smaller) has a diameter of 1.5 mm and the right outlet (larger), 2 mm. The length of the main stem, left branch and right branch are fixed at 35 mm, 20 mm and 25 mm respectively. Viscosity change that occurs in the blood leads to different parametrical changes in blood flow. The blood flow towards the smaller branch is significantly affected by the changed blood viscosity. Extended regions of high pressure and increased velocity towards the larger outlet are obtained. The Time Averaged Wall Shear Stress (TAWSS) for the corona affected artery is found to be 10.4114 Pa at a 90° angle of bifurcation as compared to 2.45002 Pa of the normal artery. For varying angles of bifurcation, an angle of 75° was found to have a maximum Time Averaged Wall Shear Stress of 2.46076 Pa and 10.42542 Pa for normal and corona affected artery, respectively.

Numerical simulation of hemodynamics frameless aortic valve bioprosthesis

This study describes an integrated approach biomechanics to modeling of a frameless prosthetic heart valve based on the analysis of medical graphic data (multispiral computed tomography), solid modeling (Abaqus/CAE) and numerical analysis of blood flow (OpenFOAM). The object of the study was the clinical case of patient D. (56 years old), who was surgically implanted with the “TiAra” aortic valve prosthesis. In this work, we reconstructed three-dimensional computer models of the functioning of the prosthesis for 10 segments of one cardiac cycle, followed by numerical experiments reproducing the movement of the key points of the product –commissural racks, leaflets. High asymmetric mobility of the bioprosthesis elements was shown during deformations of the heart cycle – one of the racks is much more mobile than the other two (up to 32% in movement). Solid modeling of the prosthesis deformation did not reveal significant malfunctioning or exceeding the stress-strain state of the components: Mises stress maximum reached 0.8 MPa. The distribution of stress indicators on the diagrams of three-dimensional models revealed the main concentration in the leaflet bell and commissural racks. In addition, qualitatively, the operation of the cusp apparatus corresponded to the functioning conditions – the dynamics of pressure changes in the structure of the cardiac cycle “systole diastole”, area of cusps contact, and the elastic properties of the materials. The analysis of the flow simulation results determined the presence of several sections with a turbulent structure in the region of the Valsalva sinuses, which, however, did not demonstrate critical quantitative characteristics – wall shear stresses (up to 74 MPa), flow velocities (0.1–1.0 m/s).

A Numerical Analysis of Blood Flow in Clogged Artery

The artery wall gets stressed due to the variation in pressure of the blood flow passing through it. When this pressure subsides, these arterial walls dilate in reaction to increasing blood pressure and contract. The additional simulation focused on determining when there is a blockage inside an artery, the velocity and wall shear stress. The current simulation focused on determining the velocity, pressure and wall shear stress when there is a different stages of blockage present inside an artery. This paper has extended the simulation with the blockage developed at the symmetric or asymmetric condition inside the arteries. The analysis of blockage expressed with flow contour, pressure, wall shear stress and velocity. This work explains completed simulations with 10% to 80% blockage at different Reynolds number as 50,100,500,1000, and 4000. More particularly, focused on understanding the functioning and morbidity related to vital organs of the human anatomy with maximum shear stress. The result suggested that how these parameters vary according to the above stated cases and the stage of critical situation. The parameters set in the study at hand aim to resolve the complexity of the procedure by eons and can be utilized in placing a design of set apparatus which will greatly help in increasing the mortality among ailing humans.

Numerical analysis of blood flow in intracranial artery stenosis affected by ischemic stroke using Finite Element method

Intracranial stenosis is a narrowing an artery inside the brain. This causes reduced blood flow to the cerebrum and damaged neurons in a short span of time due to reduced oxygenation. Intracranial stenosis can cause ischemic stroke due to a plaque occlusion. This research uses a mathematical model that expresses the velocity of arterial flow of an intracranial stenosis causing ischemic stroke that is expressed by the momentum equation and solved using the finite element method. The analysis of blood velocity is simulated using MATLAB and FLUENT software. This study looks at the effect of plaque thickness and initial speed of blood flow during an intracranial stenosis. The results shows that the larger the plaque thickness, the smaller the area reduction, so the greater the increases blood velocity and the higher the initial velocity of blood that given, the greater the increase of the initial velocity of blood in the artery Intracranial stenosis. According to the MATLAB simulation, blood velocity with 80% plaque thickness increases blood velocity to 1.8665 m/sec at rest and 1.8825 m/sec at exercises. When the initial velocity of blood was 0.2 m/sec, it increases to 0.5712 m/sec at rest and 0.70058 m/sec at exercises.

血管中の血液の流れ解析(一般講演 A3)

血管中の血液の流れ解析(一般講演 A3)

Numerical analysis of blood flow through an elliptic stenosis using large eddy simulation.

The presence of a stenosis caused by the abnormal narrowing of the lumen in the artery tree can cause significant variations in flow parameters of blood. The original flow, which is believed to be laminar in most situations, may turn out to turbulent by the geometric perturbation created by the stenosis. Flow may evolve to fully turbulent or it may relaminarise back according to the intensity of the perturbation. This article reports the numerical simulation of flow through an eccentrically located asymmetric stenosis having elliptical cross section using computational fluid dynamics. Large eddy simulation technique using dynamic Smagorinsky sub-grid scale model is applied to capture the turbulent features of flow. Analysis is carried out for two situations: steady inflow as ideal condition and pulsatile inflow corresponding to the actual physiological condition in common carotid artery. The spatially varying pulsatile inflow waveforms are mathematically derived from instantaneous mass flow measurements available in the literature. Carreau viscosity model is used to estimate the effect of non-Newtonian nature of blood. The present simulations for steady and pulsatile conditions show that post-stenotic flow field undergoes transition to turbulence in all cases. The characteristics of mean and turbulent flow fields have been presented and discussed in detail.

1303 STA-MCAバイパス術の施術効果に関する血流数値解析

1303 STA-MCAバイパス術の施術効果に関する血流数値解析

Numerical analysis of blood flow within blood pumps

Numerical analysis of blood flow within blood pumps

Numerical analysis of blood flow in the left ventricle partially supported with a continuous flow pump

Numerical analysis of blood flow in the left ventricle partially supported with a continuous flow pump

Study of arterial hemodynamics using programs medical image processing and finite element analysis

The aspects of mathematical modeling of the artery was examined in this article. The numerical analysis of blood flow through the arery was carried ut. Computer 3D-model was built using the program MIMICS for 3Dsynthesis and processing medical images. Blood was assumed to be homogeneous, incompressible Newtonian fluid. The finiteelement package Ansys was used for blood flow study. Analysis of obtained data shows a significant influence of artery narrowing upon blood flow behavior.

8F-15 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予測(OS-1(2) 循環器系のバイオメカニクスと医療機器設計(3))

8F-15 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予測(OS-1(2) 循環器系のバイオメカニクスと医療機器設計(3))

Stenotic interaction on haemodynamic parameters in double stenoses

A numerical analysis of blood flow in a rigid artery has been performed to observe the variations in flow pattern and haemodynamic parameters under the influence of multiple (double) stenoses. The interspacing distance, degree of stenotic severity and Reynolds number of flow have been varied. It is found that two stenoses interact when the interspacing distance is lower than a critical value that corresponds to the redevelopment length of fully developed flow after the proximal stenosis. In the case of non-interacting stenoses the haemodynamic parameters, like the peak centreline velocity (representing the peak systolic velocity ratio in medical term), the maximum wall shear stress, region of low shear stress and the irrecoverable pressure drop at the stenosis site, repeat themselves at each individual stenosis. However, when the stenoses interact hydrodynamically because of their proximity, the parameters behave differently, which can lead to a different haemodynamic profile in the arteries and pose difficulties in their pathological interpretation. This work evaluates the influence of double stenoses on the variations in the key haemodynamic features under different degree of stenoses and interspacing distance between the stenoses.