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المؤلفOlcay, A. B.
المؤلفAmindari, A.
المؤلفKirkkopru, K.
المؤلفYalcin, H. C.
تاريخ الإتاحة2018-03-20T06:08:44Z
تاريخ النشر2018-03-01
اسم المنشورJournal of Applied Fluid Mechanics JAFM
المعرّفhttp://dx.doi.org/10.29252/jafm.11.02.28185
الرقم المعياري الدولي للكتاب17353572
معرّف المصادر الموحدwww.jafmonline.net
معرّف المصادر الموحدhttps://goo.gl/S7xr2a
معرّف المصادر الموحدhttp://hdl.handle.net/10576/6439
الملخصIsfahan University of Technology. The aortic valve is located at left ventricular outlet and is exposed to the highest pressure in the cardiovascular system. Problems associated with the valve leaflet movement can cause complications for the heart. Specifically, aortic stenosis (AS) arises when aortic leaflets do not efficiently open. In the present study, Lagrangian Coherent Structures (LCSs) were utilized by processing a variety of Computational Fluid Dynamics (CFD) models velocity vector data further to identify the characteristics of AS jets. Particularly, effective orifice areas (EOA) for different cases were accurately identified from unstable manifolds of finite time Lyapunov exponent (FTLE) fields. Calcified leaflets were modeled by setting the leaflet's Young modulus to 10 MPa and 20 MPa for moderately and severely calcified leaflets respectively while a healthy leaflet's Young modulus was assigned to be 2 MPa. Increase in calcification degree of the leaflet caused destruction of the vortex structures near the fibrosa layer of the leaflet indicating a malfunctioning for the movement mechanism of the leaflet. Furthermore, when we analyzed stable manifolds, we identified a blockage region at the flow upstream due to the stagnant blood here. Compared to a healthy case, for the calcified valve, this blockage region was enlarged, implying an increase in AS jet velocity and wall shear stress on leaflets. As a conclusion, results from the present study indicate that aortic leaflet malfunctioning could be accurately evaluated when LCS technique was employed by post processing velocity vector data from CFD. Such precise analysis is not possible using the Eulerian CFD approach or a Doppler echocardiography since these methods are based on only analyzing instantaneous flow quantities and they overlook fluid flow characteristics of highly unsteady flows.
اللغةen
الناشرJAFM
الموضوعAortic valve
Calcification
Computational fluid dynamics
Fluid structure interaction
Hemodynamics
Lagrangian coherent structures
Pressure
Stenosis
Vortex
Wall shear stress
العنوانCharacterization of disturbed hemodynamics due to stenosed aortic jets with a Lagrangian Coherent structures technique
النوعArticle
الصفحات375-384
رقم العدد2
رقم المجلد11
ESSN1735-3645
dc.accessType Open Access


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