Studi Experimental Pengaruh Penambahan Riblet Terhadap Kinerja Aerodinamik NACA 0026: Studi Kasus Untuk Riblet Tipe Transversal V-Riblet Dengan Ukuran S = H = 3 mm

Haydar, Abdurrahman (2025) Studi Experimental Pengaruh Penambahan Riblet Terhadap Kinerja Aerodinamik NACA 0026: Studi Kasus Untuk Riblet Tipe Transversal V-Riblet Dengan Ukuran S = H = 3 mm. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Ketika fluida mengalir di sekitar airfoil, aliran mengalami perubahan momentum signifikan di area Favorable Pressure Gradient (FPG) dan cenderung melemah di area Adverse Pressure Gradient (APG), yang memicu separasi aliran akibat hilangnya kemampuan fluida mengikuti kontur airfoil, sehingga meningkatkan drag akibat turbulensi di wake belakang airfoil. Penelitian ini bertujuan meningkatkan efisiensi aerodinamis NACA 0026 melalui penerapan riblet tipe V dengan S = H = 3 mm, yang diharapkan dapat menunda separasi aliran, mengurangi drag, dan memperpanjang sudut serang sebelum stall, memberikan kontribusi pada desain airfoil efisien untuk aplikasi penerbangan dan energi.
Untuk mencapai tujuan ini, eksperimen akan dilakukan menggunakan terowongan angin subsonik dengan variasi sudut serang -15°, -10°, -5°, 0°, 5°, 10°, 15° dan variasi bilangan Reynolds 1×105, 1.5×105, serta 2×105. Riblet akan dipasang pada 25-30% panjang chord airfoil pada bagian upper surface untuk menguji efek lokal riblet terhadap kinerja aerodinamis secara keseluruhan. Metode pengujian meliputi pengukuran gaya angkat, gaya hambat, dan koefisien pressure disepanjang permukaan airfoil melalui pengaturan variasi kecepatan dan sudut.
Hasil penelitian menunjukkan bahwa penambahan riblet pada airfoil NACA 0026 sedikit meningkatkan lift pada angle of attack positif, tetapi juga meningkatkan drag akibat membesarnya daerah wake. Riblet membantu menstabilkan aliran pada angle of attack tinggi dengan meningkatkan momentum udara, namun ukurannya yang besar justru meningkatkan drag secara signifikan, sehingga rasio CL/CD menurun dan performa aerodinamik airfoil lebih rendah dibandingkan airfoil tanpa riblet. Pengujian force balance menunjukkan bahwa peningkatan CL akibat riblet hanya terjadi pada kecepatan 1.5×105 dalam jumlah kecil, sedangkan drag meningkat di semua variasi kecepatan dan angle of attack. Selain itu, peningkatan bilangan Reynolds meningkatkan stabilitas aliran dan mengurangi kemungkinan pemisahan aliran, baik pada airfoil dengan maupun tanpa riblet.
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When fluid flows around an airfoil, the flow undergoes significant momentum changes in the Favorable Pressure Gradient (FPG) area it tends to weaken in the Adverse Pressure Gradient (APG) area, which triggers flow separation due to the loss of fluid's ability to follow the airfoil contour, thereby increasing drag due to turbulence in the wake behind the airfoil. This study aims to improve the aerodynamic efficiency of NACA 0026 through the application of a V-type riblet with S = H = 3 mm, which is expected to delay flow separation, reduce drag, and extend the angle of attack before stall, contributing to the design of efficient airfoils for aviation and energy applications.
To achieve this goal, experiments will be conducted using a subsonic wind tunnel with angle of attack variations of -15°, -10°, -5°, 0°, 5°, 10°, 15° and Reynolds number variations of 1×105, 1.5×105, and 2×105. Riblets will be installed at 25-30% of the airfoil chord length on the upper surface to test the local effects of riblets on overall aerodynamic performance. The test method includes measuring lift force, drag force, and pressure coefficient along the airfoil surface through speed and angle variation settings.
The results show that the addition of riblets to the NACA 0026 airfoil slightly increases lift at positive angles of attack, but also increases drag due to the enlargement of the wake region. Riblets help stabilize the flow at high angles of attack by increasing air momentum, but their large size increases drag significantly, so the CL/CD ratio decreases and the aerodynamic performance of the airfoil is lower than the airfoil without riblets. Force balance tests show that the increase in CL due to riblets only occurs at 1.5×105 in small amounts, while drag increases in all variations of speed and angle of attack. In addition, increasing the Reynolds number improves flow stability and reduces the possibility of flow separation, both in airfoils with and without riblets.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Airfoil NACA 0026, Drag, Lift, Separation, V-Riblet, Airfoil NACA 0026, Drag, Lift, Separasi, V-Riblet.
Subjects:	T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL507.G77 Vortex generators. T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL521 Aerodynamics, Hypersonic. T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL671.9 Airplanes--Maintenance and Repair
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Abdurrahman Haydar
Date Deposited:	05 Feb 2025 08:49
Last Modified:	05 Feb 2025 08:51
URI:	http://repository.its.ac.id/id/eprint/118394

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