scholarly journals Study of Non-Newtonian biomagnetic blood flow in a stenosed bifurcated artery having elastic walls

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hasan Shahzad ◽  
Xinhua Wang ◽  
Ioannis Sarris ◽  
Kaleem Iqbal ◽  
Muhammad Bilal Hafeez ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Blood Flow ◽  
Power Law ◽  
Hartmann Number ◽  
Fluid Structure Interaction ◽  
Shear Stresses ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Power Law Index ◽  
Elastic Walls

AbstractFluid structure interaction (FSI) gained attention of researchers and scientist due to its applications in science fields like biomedical engineering, mechanical engineering etc. One of the major application in FSI is to study elastic wall behavior of stenotic arteries. In this paper we discussed an incompressible Non-Newtonian blood flow analysis in an elastic bifurcated artery. A magnetic field is applied along $$x$$ x direction. For coupling of the problem an Arbitrary Lagrangian–Eulerian formulation is used by two-way fluid structure interaction. To discretize the problem, we employed $$P_{2} P_{1}$$ P 2 P 1 finite element technique to approximate the velocity, displacement and pressure and then linearized system of equations is solved using Newton iteration method. Analysis is carried out for power law index, Reynolds number and Hartmann number. Hemodynamic effects on elastic walls, stenotic artery and bifurcated region are evaluated by using velocity profile, pressure and loads on the walls. Study shows there is significant increase in wall shear stresses with an increase in Power law index and Hartmann number. While as expected increase in Reynolds number decreases the wall shear stresses. Also load on the upper wall is calculated against Hartmann number for different values of power law index. Results show load increases as the Hartmann number and power law index increases. From hemodynamic point of view, the load on the walls is minimum for shear thinning case but when power law index increased i.e. for shear thickening case load on the walls increased.

scholarly journals Computational Investigation of the Stability of Stenotic Carotid Artery under Pulsatile Blood Flow Using a Fluid-Structure Interaction Approach

2020 ◽  
pp. 2050110
Author(s):  
Amirhosein Manzoori ◽  
Famida Fallah ◽  
Mohammadali Sharzehee ◽  
Sina Ebrahimi
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Fluid Structure Interaction ◽  
Circumferential Stress ◽  
Artery Stenosis ◽  
Shear Stresses ◽  
Pulsatile Blood Flow ◽  
Fluid Structure ◽  
Structure Interaction ◽  
The Stability

Stenosis can disrupt the normal pattern of blood flow and make the artery more susceptible to buckling which may cause arterial tortuosity. Although the stability simulations of the atherosclerotic arteries were conducted based on solid modeling and static internal pressure, the mechanical stability of stenotic artery under pulsatile blood flow remains unclear while pulsatile nature of blood flow makes the artery more critical for stresses and stability. In this study, the effect of stenosis on arterial stability under pulsatile blood flow was investigated. Fluid–structure interaction (FSI) simulations of artery stenosis under pulsatile flow were conducted. 3D idealized geometries of carotid artery stenosis with symmetric and asymmetric plaques along with different percentages of stenosis were created. It was observed that the stenosis percentage, symmetry/asymmetry of the plaque, and the stretch ratio can dramatically affect the buckling pressure. Buckling makes the plaques (especially in asymmetric ones) more likely to rupture due to increasing the stresses on it. The dominant stresses on plaques are the circumferential, axial and radial ones, respectively. Also, the highest shear stresses on the plaques were detected in [Formula: see text] and [Formula: see text] planes for the symmetric and asymmetric stenotic arteries, respectively. In addition, the maximum circumferential stress on the plaques was observed in the outer point of the buckled configuration for symmetric and asymmetric stenosis as well as at the ends of the asymmetric plaque. Furthermore, the artery buckling causes a large vortex flow at the downstream of the plaque. As a result, the conditions for the penetration of lipid particles and the formation of new plaques are provided.

scholarly journals Computational Investigation of the Stability of Stenotic Carotid Artery under Pulsatile Blood Flow Using a Fluid-Structure Interaction Approach

2020 ◽  
Author(s):  
Amirhosein Manzoori ◽  
Famida Fallah ◽  
Mohammadali Sharzehee ◽  
Sina Ebrahimi
Keyword(s):  
Blood Flow ◽  
Plaque Rupture ◽  
Fluid Structure Interaction ◽  
Circumferential Stress ◽  
Shear Stresses ◽  
Pulsatile Blood Flow ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Lipid Particles ◽  
The Stability

Abstract Background Stenosis can disrupt the normal pattern of blood flow, and thus make the artery more susceptible to buckling which may cause arterial tortuosity. Although the stability simulations of the atherosclerotic arteries were conducted based on solid modelling and static internal pressure, the mechanical stability of stenotic artery under pulsatile blood flow remains unclear while pulsatile nature of blood flow makes the artery more critical for stresses and stability. The aim of this study was to investigate the effect of stenosis on arterial stability under pulsatile blood flow. Methods To this end, fluid-structure interaction (FSI) simulations of arteries stenosis under pulsatile flow were conducted. 3D idealized geometries of carotid arteries stenosis with symmetric and asymmetric plaques along with different percentages of stenosis were created. Arterial wall was modelled as an anisotropic hyperelasic material. Results It is observed that the stenosis percentage, symmetry/asymmetry of the plaque, and the stretch ratio can dramatically affect the buckling pressure. Buckling makes the plaque rupture (especially in asymmetric ones) more likely due to increasing the stresses on it. The dominant stresses on plaques are the circumferential, axial and radial ones, respectively. Also, the highest shear stresses on the plaques were detected in \theta -z and r-\theta planes for the symmetric and asymmetric stenotic arteries, respectively. In addition, the maximum circumferential stress on the plaques was observed in the outer point of the buckled configuration for symmetric and asymmetric stenosis as well as at the ends of the asymmetric plaque. Furthermore, the artery buckling caused a large vortex flow at the downstream of the plaque. As a result, the conditions for the penetration of lipid particles and the formation of new plaques were provided. Conclusion Buckling makes the plaque rupture more likely due to increasing the stresses on it especially in asymmetric plaques. In addition, the artery buckling provides the condition for the penetration of lipid particles and the formation of new plaques at the downstream of the plaque.

Modeling of aortic valve stenosis using fluid-structure interaction method

Perfusion ◽  
2021 ◽  
pp. 026765912199854
Author(s):  
Mohammad Javad Ghasemi Pour ◽  
Kamran Hassani ◽  
Morteza Khayat ◽  
Shahram Etemadi Haghighi
Keyword(s):  
Blood Flow ◽  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Relaxation Phase ◽  
Exercise Condition ◽  
Time Dependent Domain ◽  
Comparison Of The Results

Background and objectives: Fluid structure interaction (FSI) is defined as interaction of the structures with contacting fluids. The aortic valve experiences the interaction with blood flow in systolic phase. In this study, we have tried to predict the hemodynamics of blood flow through a normal and stenotic aortic valve in two relaxation and exercise conditions using a three-dimensional FSI method. Methods: The aorta valve was modeled as a three-dimensional geometry including a normal model and two others with 25% and 50% stenosis. The geometry of the aortic valve was extracted from CT images and the models were generated by MMIMCS software and then they were implemented in ANSYS software. The pulsatile flow rate was used for all cases and the numerical simulations were conducted based on a time-dependent domain. Results: The obtained results including the velocity, pressure, and shear stress contours in different systolic time sequences were explained and discussed. The maximum blood flow velocity in relaxation phase was obtained 1.62 m/s (normal valve), 3.78 m/s (25% stenosed valve), and 4.73 m/s (50% stenosed valve). In exercise condition, the maximum velocities are 2.86, 4.32, and 5.42 m/s respectively. The maximum blood pressure in relaxation phase was calculated 111.45 mmHg (normal), 148.66 mmHg (25% stenosed), and 164.21 mmHg (50% stenosed). However, the calculated values in exercise situation were 129.57, 163.58, and 191.26 mmHg. The validation of the predicted results was also conducted using existing literature. Conclusions: We believe that such model are useful tools for biomechanical experts. The further studies should be done using experimental data and the data are implemented on the boundary conditions for better comparison of the results.

Experimental analysis of fluid-structure interaction in flexible wings at low Reynolds number flows

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mustafa Serdar Genç ◽  
Hacımurat Demir ◽  
Mustafa Özden ◽  
Tuna Murat Bodur
Keyword(s):  
Reynolds Number ◽  
Aspect Ratio ◽  
Fluid Structure Interaction ◽  
Leading Edge ◽  
Flexible Wings ◽  
Flexible Membrane ◽  
Fluid Structure ◽  
Content Type ◽  
Structure Interaction ◽  
Membrane Deformations

Purpose The purpose of this exhaustive experimental study is to investigate the fluid-structure interaction in the flexible membrane wings over a range of angles of attack for various Reynolds numbers. Design/methodology/approach In this paper, an experimental study on fluid-structure interaction of flexible membrane wings was presented at Reynolds numbers of 2.5 × 104, 5 × 104 and 7.5 × 104. In the experimental studies, flow visualization, velocity and deformation measurements for flexible membrane wings were performed by the smoke-wire technique, multichannel constant temperature anemometer and digital image correlation system, respectively. All experimental results were combined and fluid-structure interaction was discussed. Findings In the flexible wings with the higher aspect ratio, higher vibration modes were noticed because the leading-edge separation was dominant at lower angles of attack. As both Reynolds number and the aspect ratio increased, the maximum membrane deformations increased and the vibrations became visible, secondary vibration modes were observed with growing the leading-edge vortices at moderate angles of attack. Moreover, in the graphs of the spectral analysis of the membrane displacement and the velocity; the dominant frequencies coincided because of the interaction of the flow over the wings and the membrane deformations. Originality/value Unlike available literature, obtained results were presented comparatively using the sketches of the smoke-wire photographs with deformation measurement or turbulence statistics from the velocity measurements. In this study, fluid-structure interaction and leading-edge vortices of membrane wings were investigated in detail with increasing both Reynolds number and the aspect ratio.

PERSONALIZED FSI-MODELING OF THE AORTIC BULB AND ARCH TO PREDICT ITS MECHANICAL BEHAVIOR AND ASSESS THE LOADS DURING THE CARDIAC CYCLE

2021 ◽  
Vol 11 (2) ◽  
pp. 13-16
Author(s):  
Artur Ovsepyan ◽  
Alexander Smirnov ◽  
Sergey Dydykin ◽  
Yuriy Vasil'ev ◽  
Evgeniy Trunin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Mechanical Behavior ◽  
Dynamic Model ◽  
Cardiac Cycle ◽  
Fluid Structure Interaction ◽  
Complex Dynamic ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dynamic Event

The interaction of the blood flow with the aorta is a complex dynamic event described in biomechanics as the Fluid-structure interaction. In this study we’ve developed a method for creation of a personalized 3D dynamic model of the aortic bulb and arch for the prediction of its mechanical behavior using FSI-analysis. We found that the accuracy of predicting geometric aortic deformities based on FSI modeling is on average 92%.

Fluid-Structure Interaction Simulation of Blood Flow Inside a Diseased Left Ventricle With Obstructive Hypertrophic Cardiomyopathy in Early Systole

2009 ◽  
Author(s):  
Ahmad Moghaddaszade-Kermani ◽  
Peter Oshkai ◽  
Afzal Suleman
Keyword(s):  
Blood Flow ◽  
Hypertrophic Cardiomyopathy ◽  
Left Ventricle ◽  
Fluid Structure Interaction ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Systolic Phase

Mitral-Septal contact has been proven to be the cause of obstruction in the left ventricle with hypertrophic cardiomyopathy (HC). This paper presents a study on the fluid mechanics of obstruction using two-way loosely coupled fluid-structure interaction (FSI) methodology. A parametric model for the geometry of the diseased left ventricular cavity, myocardium and mitral valve has been developed, using the dimensions extracted from magnetic resonance images. The three-element Windkessel model [1] was modified for HC and solved to introduce pressure boundary condition to the aortic aperture in the systolic phase. The FSI algorithm starts at the beginning of systolic phase by applying the left ventricular pressure to the internal surface of the myocardium to contract the muscle. The displacements of the myocardium and mitral leaflets were calculated using the nonlinear finite element hyperelastic model [2] and subsequently transferred to the fluid domain. The fluid mesh was moved accordingly and the Navier-Stokes equations were solved in the laminar regime with the new mesh using the finite volume method. In the next time step, the left ventricular pressure was increased to contract the muscle further and the same procedure was repeated for the fluid solution. The results show that blood flow jet applies a drag force to the mitral leaflets which in turn causes the leaflet to deform toward the septum thus creating a narrow passage and possible obstruction.

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