Studi Numerik Pengaruh Pemasangan Riblet Segitiga Terhadap Perubahan Karakteristik Aliran Pada Airfoil Simetri NACA 0026 “Studi Kasus Riblet Segitiga Ukuran S = H = 0,5 mm, Orientasi: Longitudinal, Alignment: Indented”

Wibisono, Nur Ahmad (2026) Studi Numerik Pengaruh Pemasangan Riblet Segitiga Terhadap Perubahan Karakteristik Aliran Pada Airfoil Simetri NACA 0026 “Studi Kasus Riblet Segitiga Ukuran S = H = 0,5 mm, Orientasi: Longitudinal, Alignment: Indented”. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Performa aerodinamika airfoil berperan penting dalam menentukan efisiensi pesawat terbang, terutama melalui karakteristik gaya angkat dan gaya hambat yang dihasilkan. Salah satu metode yang dikembangkan untuk memodifikasi karakteristik aliran di sekitar permukaan airfoil adalah penggunaan riblet. Penelitian ini bertujuan menganalisis pengaruh pemasangan riblet terhadap karakteristik aerodinamika airfoil NACA 0026.Penelitian ini dilakukan menggunakan simulasi numerik tiga dimensi berbasis Computational Fluid Dynamics (CFD) dengan perangkat lunak ANSYS Fluent. Simulasi dilakukan pada kecepatan freestream 8, 12, dan 16 m/s dengan variasi sudut serang -15° hingga 15°. Riblet yang digunakan berbentuk segitiga dengan ukuran alas (s) dan tinggi (h) sebesar 0,5 mm. Riblet ditempatkan secara longitudinal dengan alignment indented. Parameter yang dianalisis meliputi koefisen lift (Cl), koefisien drag (Cd), rasio lift-to-drag (Cl/Cd), kontur dan profil kecepatan, Turbulent Kinetic Energy (TKE), serta distribusi vorticity. Hasil simulasi menunjukkan bahwa efisiensi aerodinamika maksimum dicapai pada sudut serang 7,5°. Secara umum, airfoil polos menghasilkan performa aerodinamika yang lebih baik dibandingkan airfoil riblet. Penambahan riblet longitudinal indented belum efektif mengurangi gaya hambat karena peningkatan drag yang didominasi oleh pressure drag. Peningkatan gaya angkat hanya terjadi pada kecepatan 8 m/s hingga sudut serang ±10°, sedangkan pada kondisi lainnya nilai Cl cenderung lebih rendah dibandingkan airfoil polos. Selain itu, airfoil riblet mengalami stall lebih awal pada sudut serang 10°, sedangkan airfoil polos pada sudut serang 12,5°. Hasil kontur kecepatan dan TKE menunjukkan bahwa pada sudut serang yang tinggi, riblet mempercepat separasi aliran, meningkatkan intensitas turbulensi, dan menghasilkan wake yang lebih luas dibandingkan airfoil polos.
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The aerodynamic performance of an airfoil plays an important role in determining aircraft efficiency, particularly through the lift and drag characteristics it generates. One method developed to modify the flow characteristics around an airfoil surface is the use of riblets. This study aims to analyze the effect of riblet installation on the aerodynamic characteristics of a NACA 0026 airfoil. This study was conducted using three-dimensional numerical simulations based on Computational Fluid Dynamics (CFD) with ANSYS Fluent software. Simulations were performed at freestream velocities of 8, 12, and 16 m/s with angles of attack ranging from −15° to 15°. The riblets used were triangular riblets with a base width (s) and height (h) of 0.5 mm. The riblets were arranged longitudinally with an indented alignment. The parameters analyzed included the lift coefficient (Cl), drag coefficient (Cd), lift-to-drag ratio (Cl/Cd), velocity contours and profiles, Turbulent Kinetic Energy (TKE), and vorticity distribution. The simulation results show that the maximum aerodynamic efficiency was achieved at an angle of attack of 7.5°. In general, the smooth airfoil exhibited better aerodynamic performance than the riblet-equipped airfoil. The application of longitudinal indented riblets was not effective in reducing aerodynamic drag, as the increase in total drag was primarily attributed to pressure drag. An increase in lift was observed only at a freestream velocity of 8 m/s up to an angle of attack of ±10°, whereas under the remaining conditions the Cl values tended to be lower than those of the smooth airfoil. Furthermore, the riblet-equipped airfoil experienced stall earlier at an angle of attack of 10°, while the smooth airfoil stalled at 12.5°. The velocity contours and TKE distributions indicate that, at high angles of attack, the riblets accelerated flow separation, increased turbulence intensity, and produced a wider wake compared to the smooth airfoil.

Item Type: Thesis (Other)
Uncontrolled Keywords: NACA 0026, Riblet Segitiga, CFD, Koefisien Gaya Angkat, Koefisien Gaya Hambat NACA 0026, Triangular Riblet, CFD, Lift Coefficient, Drag Coefficient
Subjects: T Technology > TA Engineering (General). Civil engineering (General) > TA357 Computational fluid dynamics. Fluid Mechanics
Divisions: Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User: Nur Ahmad Wibisono
Date Deposited: 03 Aug 2026 04:42
Last Modified: 03 Aug 2026 04:42
URI: http://repository.its.ac.id/id/eprint/142004

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