Studi Numerik Pengaruh Pemasangan Riblet Segitiga terhadap Perubahan Karakteristik Aliran pada Airfoil Simetri NACA 0026 Studi Kasus Riblet Ukuran s = h = 0,5 mm, Orientasi: Longitudinal, Alignment: Protruded

Kanaya, Arnelysha (2026) Studi Numerik Pengaruh Pemasangan Riblet Segitiga terhadap Perubahan Karakteristik Aliran pada Airfoil Simetri NACA 0026 Studi Kasus Riblet Ukuran s = h = 0,5 mm, Orientasi: Longitudinal, Alignment: Protruded. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penelitian ini bertujuan mengevaluasi pengaruh pemasangan riblet segitiga protruded terhadap karakteristik aerodinamika airfoil NACA 0026 sebagai upaya meningkatkan efisiensi aerodinamika melalui pengurangan gaya hambat (drag) tanpa mengurangi gaya angkat (lift). Simulasi dilakukan menggunakan Computational Fluid Dynamics (CFD) tiga dimensi pada ANSYS Fluent dengan riblet berdimensi s = h = 0,5 mm yang dipasang pada 25–40% panjang chord permukaan atas airfoil. Variasi kecepatan aliran bebas yang digunakan adalah 8, 12, dan 16 m/s dengan sudut serang −15° hingga 15°. Model turbulensi dipilih melalui validasi terhadap XFOIL, dan model k-ω SST memberikan deviasi terkecil sebesar 0,82%. Parameter yang dianalisis meliputi koefisien drag (Cd), koefisien lift (Cl), rasio Cl/Cd, profil kecepatan, vorticity, dan turbulent kinetic energy (TKE). Hasil menunjukkan bahwa Cd minimum terjadi pada AOA 0° dan meningkat seiring bertambahnya sudut serang, sedangkan penambahan riblet cenderung meningkatkan Cd akibat skin friction. Nilai Cl meningkat hingga AOA 10° sebelum menurun pada AOA yang lebih tinggi sebagai indikasi awal stall. Ditinjau dari rasio Cl/Cd, airfoil riblet memiliki performa yang hampir sama dengan airfoil polos pada kecepatan 8 m/s, sedangkan pada kecepatan 12 m/s dan 16 m/s airfoil polos menunjukkan efisiensi aerodinamika yang lebih tinggi. Profil kecepatan kedua konfigurasi relatif serupa, sedangkan vorticity meningkat seiring bertambahnya kecepatan dan mencapai nilai tertinggi pada 16 m/s. Pengaruh riblet terutama terjadi pada daerah near-wall, belum mampu menunda separasi aliran secara signifikan, dan belum meningkatkan performa aerodinamika airfoil NACA 0026.
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This study aims to evaluate the effect of protruded triangular riblets on the aerodynamic characteristics of the NACA 0026 airfoil as an effort to improve aerodynamic efficiency by reducing drag without compromising lift. Three-dimensional Computational Fluid Dynamics (CFD) simulations were performed using ANSYS Fluent. The protruded triangular riblets, with dimensions of s = h = 0.5 mm, were installed on the upper surface of the airfoil at 25–40% of the chord length. Simulations were conducted at freestream velocities of 8, 12, and 16 m/s with angles of attack (AOA) ranging from −15° to 15°. The turbulence model was selected through validation against XFOIL, where the k–ω SST model yielded the lowest deviation of 0.82%. The evaluated parameters included the drag coefficient (Cd), lift coefficient (Cl), lift-to-drag ratio (Cl/Cd), velocity profile, vorticity, and turbulent kinetic energy (TKE).The results indicate that the minimum Cd occurred at an AOA of 0° and increased with increasing angle of attack, while the addition of riblets generally increased Cd due to higher skin-friction drag. The Cl increased up to an AOA of 10° before decreasing at higher angles of attack, indicating the stall. Based on the Cl/Cd ratio, the riblet airfoil exhibited aerodynamic performance comparable to the smooth airfoil at a freestream velocity of 8 m/s. However, at freestream velocities of 12 m/s and 16 m/s, the smooth airfoil demonstrated higher aerodynamic efficiency than the riblet airfoil. The velocity profiles of both configurations exhibited similar overall patterns, whereas the vorticity increased with freestream velocity and reached its highest value at 16 m/s. The influence of the riblets was mainly confined to the near-wall region, where they were unable to significantly delay flow separation. Consequently, the protruded triangular riblet configuration investigated in this study did not improve the overall aerodynamic performance of the NACA 0026 airfoil.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Riblet, NACA 0026, Koefisien Drag, Koefisien Lift, Riblets, NACA 0026, Drag Coefficient, Lift Coefficient
Subjects:	T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL521 Aerodynamics, Hypersonic.
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Arnelysha Kanaya
Date Deposited:	29 Jul 2026 02:42
Last Modified:	29 Jul 2026 02:42
URI:	http://repository.its.ac.id/id/eprint/138976

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