scholarly journals A Numerical Analysis of Pressure Pulsation Characteristics Induced by Unsteady Blood Flow in a Bileaflet Mechanical Heart Valve

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 232 ◽  
Author(s):  
Xiao-gang Xu ◽  
Tai-yu Liu ◽  
Cheng Li ◽  
Lu Zhu ◽  
Shu-xun Li
Keyword(s):  
Blood Flow ◽  
Heart Valves ◽  
Pressure Pulsation ◽  
Flow Direction ◽  
Mechanical Heart Valve ◽  
Opening Angle ◽  
Trailing Edges ◽  
Main Flow Direction ◽  
Flow Through ◽  
Unsteady Blood Flow

The leaflet vibration phenomenon in bileaflet mechanical heart valves (BMHVs) can cause complications such as hemolysis, leaflet damage, and valve fracture. One of the main reasons for leaflet vibration is the unsteady blood flow pressure pulsation induced by turbulent flow instabilities. In this study, we performed numerical simulations of unsteady flow through a BMHV and observed pressure pulsation characteristics under different flow rates and leaflet fully opening angle conditions. The pressure pulsation coefficient and the low-Reynolds k-ω model in CFD (Computational Fluid Dynamics) software were employed to solve these problems. Results showed that the level of pressure pulsation was highly influenced by velocity distribution, and that the higher coefficient of pressure pulsation was associated with the lower flow velocity along the main flow direction. The influence of pressure pulsation near the trailing edges was much larger than the data obtained near the leading edges of the leaflets. In addition, considering the level of pressure pulsation and the flow uniformity, the recommended setting of leaflet fully opening angle was about 80°.

An Initial Parametric Study on Fluid Flow Through Bileaflet Mechanical Heart Valves Using Computational Fluid Dynamics

1994 ◽  
Vol 208 (2) ◽  
pp. 63-72 ◽  
Author(s):  
M J King ◽  
T David ◽  
J Fisher
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Volumetric Flow Rate ◽  
Flow Fields ◽  
Opening Angle ◽  
Bileaflet Mechanical Heart Valve ◽  
Flow Through

The effect of leaflet opening angle on flow through a bileaflet mechanical heart valve has been investigated using computational fluid dynamics (CFD). Steady state, laminar flow for a Newtonian fluid at a Reynolds number of 1500 was used in the two-dimensional model of the valve, ventricle, sinus and aorta. This computational model was verified using one-dimensional laser Doppler velocimetry (LDV). Although marked differences in the flow fields and energy dissipation of the jets downstream of the valve were found between the CFD predictions and the three-dimensional experimental model, both methods showed similar trends in the changes of the flow fields as the leaflet opening angle was altered. As the opening angle increased the area of recirculating fluid downstream of the leaflets, the pressure drop across the valve and the volumetric flow rate through the outer orifice decreased. For opening angles greater than 80° the jet through the outer orifice recombined with the central jet downstream of the leaflet; for an opening angle of 78° the jet through the outer orifice impinged on the aortic wall before recombining with the central jet. This study suggests that the opening angle has a marked effect on the flow downstream of the bileaflet mechanical heart valve and that valves with opening angles greater than 80° are preferable.

Fluid Structure Interaction Analysis of Blood Flow Through a Mechanical Heart Valve

2008 ◽  
Author(s):  
Alejandro Roldán ◽  
Nancy Sweitzer ◽  
Tim Osswald ◽  
Naomi Chesler
Keyword(s):  
Blood Flow ◽  
Heart Valve ◽  
Heart Valves ◽  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Mechanical Heart Valve ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Flow Through ◽  
Domain Discretization

Modeling pulsatile flow past heart valves remains a relatively unexplored but critical area. Due to the geometric complexity and the interaction between the flowing blood and the heart valve leaflets, existing numerical techniques that require domain discretization, such as finite element methods or finite difference techniques, cannot fully represent the moving and deforming boundaries present in an operating valve. Our aim is to develop a technique to model the flow through heart valves which includes the interaction between the blood flow and the valve leaflets using the radial functions method (RFM). The RFM is a meshless technique that fully accounts for moving and deforming surfaces and thus is well suited to model the blood flow and its interaction with leaflet motion. Here we present a 2D fluid structure interaction (FSI) model of the blood flow through a bileaflet mechanical heart valve (MHV).

scholarly journals Numerical Study of Blood Flow Through Artificial Heart Valves

2021 ◽  
Vol 1094 (1) ◽  
pp. 012120
Author(s):  
Hussein Togun ◽  
Ali Abdul Hussain ◽  
Saja Ahmed ◽  
Iman Abdul hussain ◽  
Huda Shaker
Keyword(s):  
Blood Flow ◽  
Artificial Heart ◽  
Heart Valves ◽  
Numerical Study ◽  
Artificial Heart Valves ◽  
Flow Through

scholarly journals Numerical and Analytical Study of Two-Layered Unsteady Blood Flow through Catheterized Artery

PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0161377 ◽  
Author(s):  
Akbar Zaman ◽  
Nasir Ali ◽  
M. Sajid ◽  
Tasawar Hayat
Keyword(s):  
Blood Flow ◽  
Analytical Study ◽  
Catheterized Artery ◽  
Flow Through ◽  
Unsteady Blood Flow

Numerical Simulation of Blood Flow Through Heart Valves

2007 ◽  
Author(s):  
AliReza Nejadmalayeri ◽  
Klaus Hoffmann ◽  
Jean-François Dietiker
Keyword(s):  
Numerical Simulation ◽  
Blood Flow ◽  
Heart Valves ◽  
Flow Through

scholarly journals Blood Damage Through a Bileaflet Mechanical Heart Valve: A Quantitative Computational Study Using a Multiscale Suspension Flow Solver

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
B. Min Yun ◽  
Cyrus K. Aidun ◽  
Ajit P. Yoganathan
Keyword(s):  
Numerical Method ◽  
Heart Valves ◽  
Computational Study ◽  
Mechanical Heart Valve ◽  
Complex Flow ◽  
Damage Potential ◽  
Spatiotemporal Resolution ◽  
Jude Medical ◽  
Blood Damage ◽  
Flow Through

Bileaflet mechanical heart valves (BMHVs) are among the most popular prostheses to replace defective native valves. However, complex flow phenomena caused by the prosthesis are thought to induce serious thromboembolic complications. This study aims at employing a novel multiscale numerical method that models realistic sized suspended platelets for assessing blood damage potential in flow through BMHVs. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through a 23 mm St. Jude Medical (SJM) Regent™ valve in the aortic position at very high spatiotemporal resolution with the presence of thousands of suspended platelets. Platelet damage is modeled for both the systolic and diastolic phases of the cardiac cycle. No platelets exceed activation thresholds for any of the simulations. Platelet damage is determined to be particularly high for suspended elements trapped in recirculation zones, which suggests a shift of focus in blood damage studies away from instantaneous flow fields and toward high flow mixing regions. In the diastolic phase, leakage flow through the b-datum gap is shown to cause highest damage to platelets. This multiscale numerical method may be used as a generic solver for evaluating blood damage in other cardiovascular flows and devices.

Flow Patterns Downstream of a Mechanical Heart Valve During Systole

2007 ◽  
Author(s):  
P. Oshkai ◽  
F. Haji-Esmaeili
Keyword(s):  
Turbulent Flow ◽  
Heart Valve ◽  
Large Scale ◽  
Cardiac Cycle ◽  
Mechanical Heart Valve ◽  
Opening Angle ◽  
Image Velocimetry ◽  
Imaging Approach ◽  
Systolic Phase ◽  
Flow Through

Digital particle image velocimetry is employed to study turbulent flow through a bileaflet mechanical heart valve during systolic phase of a cardiac cycle. Unsteady vortex shedding from the valve’s leaflets displays distinct characteristic frequencies, depending on the opening angle of each leaflet. Small- and large-scale transverse oscillations of the separated shear layers are studied using global quantitative flow imaging approach. Turbulent flow structures including jet-like regions and shed vortices are characterized in terms of patterns of instantaneous and time-averaged velocity, vorticity, and turbulence statistics.

NUMERICAL SIMULATION OF SISKO MODEL FOR UNSTEADY BLOOD FLOW THROUGH A VESSEL

2019 ◽  
Vol 16 (1) ◽  
pp. 107-124
Author(s):  
Ida Wahidah ◽  
Sumardi ◽  
Imam Solekhudin ◽  
Lina Aryati
Keyword(s):  
Numerical Simulation ◽  
Blood Flow ◽  
Flow Through ◽  
Unsteady Blood Flow

A vortex method for blood flow through heart valves

1980 ◽  
Vol 35 (2) ◽  
pp. 183-205 ◽  
Author(s):  
M.F. McCracken ◽  
C.S. Peskin
Keyword(s):  
Blood Flow ◽  
Heart Valves ◽  
Vortex Method ◽  
Flow Through
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