شبیه‌سازی عددی لایه‌مرزی غلظت لیپوپروتئین‌های کم‌چگال در یک شریان مستقیم و بررسی اثرات تنش برشی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 خیابان طالقانی، خیابان شهید ثلاث، ثلاث2، پلاک 38

2 دانشگاه صنعتی امیرکبیر

3 صنعتی امیرکبیر*مهندسی پزشکی

چکیده

لیپوپروتئین‌های کم چگال، که به عنوان کلسترول بد شناخته می‌شوند، عامل اصلی شکل گیری عارضه تصلب شرایین به حساب می‌آیند. تجمع غیرطبیعی لیپوپروتئین‌های کم چگال در دیواره شریان و در نتیجه تشکیل اکسید می‌تواند منجر به تصلب شریان گردد. از این رو در تحقیق حاضر، لایه مرزی غلظت لیپوپروتئین‌های ک مچگال در مجرای شریانی مستقیم به صورت عددی مورد بررسی قرار گرفته است. معادلات حاکم شامل معادلات پیوستگی، بقای مومنتوم و انتقال جرم ذرات در خون با استفاده از یکی از قدرتمندترین تکنیک‌های دینامیک سیالات محاسباتی موسوم به روش تصویر تحت شرایط مرزی مناسب حل گردیده است. نتایج در قالب پروفیل‌ها و کانتورهای غلظت لیپوپروتئین‌های کم چگال، سرعت خون و تنش برشی دیواره شریان با جزییات به دست آمده و همخوانی خوبی با نتایج عددی و تحلیلی مطالعات پیشین دارد. تأثیر عواملی نظیر سرعت فیلتراسیون و تنش برشی دیواره بر غلظت سطحی لیپوپروتئین‌های کم چگال و همچنین ضخامت لایه مرزی غلظت مورد ارزیابی قرار گرفته است. نتایج نشان می‌دهد افزایش سرعت مکش دیواره شریان )فشار خون بالا( و کاهش تنش برشی دیواره موجب افرایش غلظت سطحی می‌گردد. افزایش عدد رینولدز و عدد اشمیت جریان خون موجب کاهش ضخامت لایه مرزی شده و افزایش متوسط 7 درصدی در غلظت سطحی نسبت مقدار آن در جریان آزاد مشاهده می‌شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Simulation of Low-Density Lipoprotein Concentration Boundary Layer in a Straight Artery and the Effects of Wall Shear Stress

نویسندگان [English]

  • Hossein Tamim 1
  • Abbas Abbassi 2
  • Nasser Fatouraee 3
1 خیابان طالقانی، خیابان شهید ثلاث، ثلاث2، پلاک 38
3 Biomedical Eng. department, Amirkabir Univ. of Technology
چکیده [English]

Low-density lipoprotein, which is recognized as bad cholesterol, typically has been regarded as the main cause of atherosclerosis. An abnormal accumulation of low-density lipoprotein in the artery wall and, as a result, in the formation of oxide, can lead to atherogenesis. Therefore in present study, the concentration boundary layer of low-density lipoprotein in a straight artery is investigated numerically. The governing equations consist of continuity, momentum conservation, and the particles transport in the blood based on appropriate boundary conditions have been solved using one of the most powerful computational fluid dynamics techniques known as the Projection method. Results are obtained and presented as profiles and contours of concentration, blood velocity and wall shear stress, which are in good agreement with numerical and analytical results of previous studies. Effects of factors such as filtration velocity and wall shear stress on the low-density lipoprotein surface concentration and concentration boundary layer thickness are investigated. The results show that increasing the wall suction (high blood pressure) and reducing the Wall Shear Stress results in an increase in surface concentration. Increasing Reynolds number and Schmidt number decreases the concentration boundary layer thickness, and surface concentration increase about 7% higher than that of the bulk flow.

کلیدواژه‌ها [English]

  • Projection Method
  • computational fluid dynamics
  • Low-Density Lipoprotein Transport
  • Arterial Wall
  • wall shear stress
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