Pemodelan Aliran Darah pada Kasus Central Retinal Artery Occlusion (CRAO) Menggunakan Finite Volume Method (FVM)

Muarifadila, Yuni Keputri (2026) Pemodelan Aliran Darah pada Kasus Central Retinal Artery Occlusion (CRAO) Menggunakan Finite Volume Method (FVM). Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Central Retinal Artery Occlusion (CRAO) merupakan kondisi dimana aliran darah dari arteri ke retina terhambat yang umumnya disebabkan oleh adanya emboli. Hal ini berdampak pada penurunan fungsi penglihatan secara mendadak tanpa rasa sakit. Penelitian ini berfokus pada analisis pengaruh tiga bentuk geometri asimetris (Bell-Gaussian, Gaussian-Elliptical, Bell-Elliptical), ketebalan stenosis, posisi penyempitan, dan panjang penyempitan terhadap kecepatan dan tekanan aliran darah. Aliran fluida diasumsikan unsteady, incompressible, dan Newtonian. Model matematika yang dikembangkan yaitu model aliran darah dengan pendekatan persamaan Navier-Stokes yang didiskritisasi dengan FVM (FVM) dan Algoritma Semi-Impicit Method for Pressure-Linked Equatios (SIMPLE) menggunakan MATLAB. Model divalidasi dengan membandingkan hasil simulasi peneliti dengan penelitian lain serta dilakukan perbandingan secara kualitatif pada hasil simulasi di MATLAB dan hasil simulasi di ANSYS Fluent. Hasil simulasi MATLAB menunjukkan bahwa peningkatan ketebalan stenosis menyebabkan peningkatan kecepatan dan penurunan tekanan aliran di area stenosis, terutama pada geometri Bell-Elliptical dengan ketebalan 90%. Variasi panjang stenosis tidak terlalu memengaruhi nilai kecepatan maksimum dan tekanan minimum, melainkan memengaruhi luas daerah aliran laminar di sekitar penyempitan. Sementara itu, variasi posisi penyempitan memengaruhi lokasi dan besar kecepatan maksimum dan tekanan minimum, dimana model Bell-Gaussian menghasilkan pola aliran yang lebih halus. Sedangkan hasil simulasi ANSYS Fluent menghasilkan distribusi kecepatan dan tekanan yang hampir serupa dengan MATLAB secara kualitatif. Visualisasi kontur kecepatan dan tekanan pada ANSYS Fluent menampilkan gradien yang lebih jelas di sekitar stenosis yang dilengkapi dengan vektor arah kecepatan. Penelitian ini diharapkan dapat menjadi ajang kontribusi dalam pengembangan pemodelan aliran darah pada kasus CRAO serta menjadi referensi pendukung dalam kajian hemodinamika di bidang kesehatan.
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Central Retinal Artery Occlusion (CRAO) is a condition in which blood flow from the central retinal artery to the retina is obstructed, commonly due to the presence of an embolus. This condition leads to sudden and painless loss of visual function. This study focuses on analyzing effects of three asymmetric geometric stenosis shapes (Bell–Gaussian, Gaussian–Elliptical, and Bell–Elliptical), stenosis thickness, stenosis location, and stenosis length on blood flow velocity and pressure. The blood flow is assumed to be unsteady, incompressible, and Newtonian. The mathematical model is based on the Navier–Stokes equations, which are discretized using the Finite Volume Method (FVM) and solved using the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm implemented in MATLAB. The model is validated by comparing the simulation results with those reported in previous studies, as well as through a qualitative comparison between the MATLAB simulations and results obtained from ANSYS Fluent. The MATLAB simulation results indicate that increase in stenosis thickness leads to higher flow velocity and lower pressure within the stenotic region, particularly for the Bell–Elliptical geometry with a stenosis thickness of 90%. Variations in stenosis length have a limited effect on maximum velocity and minimum pressure, but significantly influence the extent of laminar flow region around the stenosis. Meanwhile, variations in stenosis location affect both the position and magnitude of maximum velocity and minimum pressure, with the Bell–Gaussian model producing smoother flow patterns. The ANSYS Fluent simulations yield velocity and pressure distributions that are qualitatively consistent with the MATLAB results. The contour visualizations in ANSYS Fluent show clearer gradients in the stenotic region, complemented by velocity vector representations. This study is expected to contribute to the development of blood flow modeling in CRAO cases and to serve as a supporting reference for hemodynamic studies in the healthcare field.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	CRAO, aliran darah, Navier-Stokes, FVM, SIMPLE. CRAO, blood flow, Navier-Stokes, FVM, SIMPLE
Subjects:	Q Science Q Science > QA Mathematics Q Science > QA Mathematics > QA911 Fluid dynamics. Hydrodynamics
Divisions:	Faculty of Mathematics and Science > Mathematics > 44201-(S1) Undergraduate Thesis
Depositing User:	Yuni Keputri Muarifadila
Date Deposited:	29 Jan 2026 04:20
Last Modified:	29 Jan 2026 04:20
URI:	http://repository.its.ac.id/id/eprint/130938

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