scholarly journals Application of a strong FSI coupling scheme for the numerical simulation of bileaflet mechanical heart valve dynamics: study of wall shear stress on the valve leaflets

2012 ◽  
Vol 12 (2/3) ◽  
pp. 68 ◽  
Author(s):  
Sebastiaan Annerel ◽  
Joris Degroote ◽  
Jan Vierendeels ◽  
Tom Claessens ◽  
Peter Van Ransbeeck ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Heart Valve ◽  
Mechanical Heart Valve ◽  
Coupling Scheme ◽  
Bileaflet Mechanical Heart Valve ◽  
Valve Dynamics ◽  
Wall Shear ◽  
Heart Valve Dynamics

scholarly journals Comparative Study of Wall-Shear Stress at the Ascending Aorta for Different Mechanical Heart Valve Prostheses

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Qianhui Li ◽  
Franziska Hegner ◽  
Christoph H. Bruecker
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Heart Valve ◽  
Aortic Wall ◽  
Mechanical Heart Valve ◽  
Ascending Aorta ◽  
Field Analysis ◽  
Human Aorta ◽  
Wall Shear ◽  
The Impact

AbstractAn experimental study is reported which investigates the wall shear stress (WSS) distribution in a transparent model of the human aorta comparing an St. Jude Medical (SJM) Regent bileaflet mechanical heart valve (BMHV) with the Lapeyre-Triflo FURTIVA trileaflet mechanical heart valve (TMHV) in physiological pulsatile flow. Elastic microcantilever structures, calibrated as micropillar WSS sensors by microparticle-image-velocimetry measurements, are applied to the wall along the ascending aorta (AAo). The peak WSS values in the BMHV are observed to be almost twice that of the values seen in the TMHV. Flow field analysis illuminates that these peaks are linked to the jet-like flows generated in the valves interacting with the aortic wall. Not only the magnitude but also the impact regions are specific for different valve designs. The side-orifice jets generated by the BMHV travel along the aortic wall in the AAo, impacting the wall throughout the AAo. However, the jets generated by TMHV impact further downstream in the AAo and results in a reduced WSS.

scholarly journals A Computational Study of a Passive Flow Device in a Mechanical Heart Valve for the Anatomic Aorta and the Axisymmetric Aorta

CFD letters ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 69-79
Author(s):  
Nursyaira Mohd Salleh ◽  
Mohamad Shukri Zakaria ◽  
Mohd Juzaila Abd Latif ◽  
Adi Azriff Basri
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Heart Valve ◽  
Heart Valves ◽  
Computational Study ◽  
Mechanical Heart Valve ◽  
Vortex Generator ◽  
Leading Edge ◽  
Jude Medical ◽  
Wall Shear

Artificial heart valves for replacing diseased indigenous heart valves were widely used. The treatment of certain types of heart disease requires mechanical valves to be implanted operatively. Healthy cardiac valves are essential to proper cardiac function. The current study presents an investigation of the pulsatile blood flow through a bileaflet mechanical heart valve (BMHV) with a vortex generator (VG) in fully open position. A St. Jude Medical Regent valve with a diameter of 23 mm was used to mount triangular VGs as a means of improving pressure gradients and reducing turbulence. The anatomic aorta and axisymmetric aorta was computed by large eddy simulation (LES) approached. The implications for both models with VGs were observed in terms of velocity magnitude, vortices and wall shear stress. The results suggested that the anatomic aorta is prone to develop more blood clotting at the leading edge of the leaflets with 2.03 m/s. Furthermore, the anatomic aorta produces higher wall shear stress with 69Pa, which possibly contributes to a high risk of thrombosis.

scholarly journals Numerical Simulation of Dispersed Particle-Blood Flow in the Stenosed Coronary Arteries

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Mongkol Kaewbumrung ◽  
Somsak Orankitjaroen ◽  
Pichit Boonkrong ◽  
Buraskorn Nuntadilok ◽  
Benchawan Wiwatanapataphee
Keyword(s):  
Numerical Simulation ◽  
Blood Flow ◽  
Shear Stress ◽  
Coronary Artery ◽  
Pressure Drop ◽  
Wall Shear Stress ◽  
Stokes Equations ◽  
Spherical Shape ◽  
Shear Stresses ◽  
Wall Shear

A mathematical model of dispersed bioparticle-blood flow through the stenosed coronary artery under the pulsatile boundary conditions is proposed. Blood is assumed to be an incompressible non-Newtonian fluid and its flow is considered as turbulence described by the Reynolds-averaged Navier-Stokes equations. Bioparticles are assumed to be spherical shape with the same density as blood, and their translation and rotational motions are governed by Newtonian equations. Impact of particle movement on the blood velocity, the pressure distribution, and the wall shear stress distribution in three different severity degrees of stenosis including 25%, 50%, and 75% are investigated through the numerical simulation using ANSYS 18.2. Increasing degree of stenosis severity results in higher values of the pressure drop and wall shear stresses. The higher level of bioparticle motion directly varies with the pressure drop and wall shear stress. The area of coronary artery with higher density of bioparticles also presents the higher wall shear stress.

Numerical Simulation of Flow-Induced Wall Shear Stress of a One Strand Tundish Design

2011 ◽  
Vol 402 ◽  
pp. 85-89 ◽  
Author(s):  
Zhi Bing Tian ◽  
Yan Jin ◽  
Hong Yu Li
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Shear Stress ◽  
Service Life ◽  
Wall Shear Stress ◽  
Design Parameters ◽  
Horizontal Distance ◽  
Wall Shear

In this paper, the flow-induced wall shear stress on the wall of a one Strand tundish has been computed by a 3-D mathematical model. Different design parameters of the tundish such as HB(the height of the dam) and DB(the horizontal distance between the dam and the outlet of the tundish) are studied by analyzing the flow-induced wall shear stress. After a series of calculation, A modification in design parameters (DB and HB )of the tundish can reduce the wall shear stress, thus may help to improve the service life of the tundish.

scholarly journals Ascending Aorta Resection and End-to-End Anastomosis: Redistribution of Wall Shear Stress Induced by a Bioprosthetic Heart Valve

Prosthesis ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 297-303
Author(s):  
Giuseppe M. Raffa ◽  
Salvatore Pasta
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Heart Valve ◽  
Ascending Aorta ◽  
Bioprosthetic Heart Valve ◽  
Ascending Aortic Aneurysm ◽  
Hemodynamic Forces ◽  
Lack Of Information ◽  
End To End ◽  
Wall Shear

Although aortic resection and end-to-end anastomosis are applied to repair ascending aortic aneurysm, there is a lack of information on the late risk of post-operative complications, such as aortic dissection and aneurysmal re-dilatation. It is recognized that altered hemodynamic forces exerted on an aortic wall play an important role on dissection and aneurysm formation. We present a case in which the hemodynamic forces were investigated prior and after repair of an ascending aorta treated by resection with end-to-end anastomosis and a bioprosthetic heart valve. Post-operative wall shear stress was redistributed uniformly along the vessel circumference, and this may suggest a reduced risk of complications near aortic root, but not exclude the re-dilatation of the ascending aorta.

Numerical Simulation of Flow Distribution and Wall Shear Stress Downstream from an Orifice

2016 ◽  
Vol 2016.21 (0) ◽  
pp. D113
Author(s):  
Shungo MATSUMURA ◽  
Takahiro KIWATA ◽  
Atsusi KAWAI ◽  
Yoichi UTANOHARA ◽  
Takaaki KONO
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Distribution ◽  
Wall Shear

Performance Prediction for Optical Wall Shear Stress Sensor Using Direct Numerical Simulation of Fluid Flow

2003 ◽  
Author(s):  
Katsuaki Shirai ◽  
Keisuke Tsuru ◽  
Shinnosuke Obi
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Direct Numerical Simulation ◽  
Performance Prediction ◽  
Stress Sensor ◽  
Doppler Signals ◽  
Shear Stress Sensor ◽  
Wall Shear ◽  
Yaw Angle

We conducted a performance prediction for an optical wall shear stress sensor with using the velocity data of a direct numerical simulation. The Doppler signals were generated with respect to the path of tracer particles passing through the measurement volume. A signal processing technique was proposed to estimate the magnitude and yaw angle of local wall shear stress simultaneously from each Doppler signal. The simulated Doppler signals were processed with the technique, however the accuracy of estimating the yaw angle is not sufficient. In contrast, the estimated magnitude of wall shear stress showed a good agreement with the direct estimate from the DNS data if the yaw angle was accurately estimated. The measurement accuracy of the sensor mainly depends on estimating the yaw angle of each tracer particle. Another technique for detecting the yaw angle is needed for the accurate measurement of both the yaw angle and magnitude of local wall shear stress.

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