Studi Numerik Pengaruh Penambahan Rectangular Bump Terhadap Karakteristik Aerodinamika Pada Airfoil NACA 0012

Falah, Fajrul (2024) Studi Numerik Pengaruh Penambahan Rectangular Bump Terhadap Karakteristik Aerodinamika Pada Airfoil NACA 0012. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Abstrak

Airfoil adalah bentuk aerodinamika yang menghasilkan gaya lift dan meminimalkan gaya hambat (drag force). Drag force dapat mengurangi gaya angkat, menyebabkan separasi aliran, dan stall pada sudut serang tertentu. Untuk mencegah ini, aliran harus memiliki momentum yang cukup untuk mengikuti kontur airfoil, dengan aliran turbulen memperlambat separasi karena momentumnya yang kuat. Penelitian ini bertujuan mengubah aliran menjadi turbulen segera setelah no slip condition pada leading edge.
Penelitian dilakukan secara numerik menggunakan airfoil NACA 0012 dengan chord panjang 250 mm yang diberi bump berbentuk rectangular pada area favorable pressure gradient. Variasi dilakukan pada peletakan bump yang dianotasikan sebagai B/C atau titik peletakan bump terhadap chord: 25%, 50%, dan 75% sebelum maximum thickness. Selain itu, variasi juga dilakukan dengan angle of attack (AOA) 0°, 4°, 8°, dan 12°. Penelitian ini menggunakan Reynold’s Number 6x10^6dan streamline velocity 52 m/s. Analisa dilakukan dalam 2-D menggunakan software ANSYS Fluent.
Hasil penelitian menunjukkan bahwa penambahan rectangular bump pada airfoil menimbulkan bubble separation. Pada AOA rendah, bubble tetap melekat pada permukaan airfoil, menunda separasi, sementara pada AOA tinggi, airfoil lebih rentan terhadap separasi cepat, menyebabkan stall. Penempatan bump yang efektif untuk menghasilkan bubble adalah pada B/C = 0,15, diikuti oleh B/C = 0,225, dan B/C = 0,075. Penempatan bump yang terlalu awal atau terlambat tidak efektif. Namun, bubble yang terbentuk belum mampu meningkatkan performa airfoil secara signifikan, ditandai dengan rasio Cl/Cd yang masih lebih rendah dibandingkan dengan airfoil polos.

Kata kunci: Airfoil NACA 0012, Bump, Turbulen, Studi Numerik

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Abstract

An airfoil is an aerodynamic shape that generates lift force and minimizes drag force. Drag forces can reduce lift, cause flow separation, and stall at certain angles of attack. To prevent this, the flow must have enough momentum to follow the contours of the airfoil, with turbulent flow slowing down the separation due to its strong momentum. This study aims to convert the flow to turbulent immediately after the no slip condition at the leading edge.
The research was conducted numerically using NACA 0012 airfoil with a chord length of 250 mm which was given a rectangular bump in the favorable pressure gradient area. Variations were made on the placement of the bump which is annotated as B/C or the point of bump placement against the chord: 25%, 50%, and 75% before maximum thickness. In addition, variations were also made with angle of attack (AOA) of 0°, 4°, 8°, and 12°. This study used Reynold's Number 6x10^6 and streamline velocity 52 m/s. The analysis was conducted in 2-D using ANSYS Fluent software.
The results show that the addition of rectangular bump to the airfoil causes bubble separation. At low AOA, the bubble remains attached to the airfoil surface, delaying separation, while at high AOA, the airfoil is more prone to rapid separation, causing stall. The effective bump placement to generate bubbles is at B/C = 0.15, followed by B/C = 0.225, and B/C = 0.075. Bump placement that is too early or too late is not effective. However, the bubbles formed have not been able to significantly improve the airfoil performance, characterized by a Cl/Cd ratio that is still lower than that of the plain airfoil.

Keywords: NACA 0012 Airfoil, Bump, Turbulent, Numerical Study

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Airfoil NACA 0012, Bump, Turbulen, Studi Numerik, NACA 0012 Airfoil, Bump, Turbulent, Numerical Study
Subjects:	T Technology > T Technology (General) > T57.62 Simulation T Technology > T Technology (General) > T58.8 Productivity. Efficiency T Technology > TJ Mechanical engineering and machinery T Technology > TJ Mechanical engineering and machinery > TJ230 Machine design T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL521 Aerodynamics, Hypersonic. T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL574.C3 Cascade
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Fajrul Falah
Date Deposited:	12 Aug 2024 02:25
Last Modified:	12 Aug 2024 02:25
URI:	http://repository.its.ac.id/id/eprint/113984

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