Studi Numerik Pengaruh Penambahan Triangular Bump Terhadap Karakteristik Aliran Di Atas Pelat Datar Dengan Perubahan Bilangan Reynolds

Taufik, Kanya Aisha (2025) Studi Numerik Pengaruh Penambahan Triangular Bump Terhadap Karakteristik Aliran Di Atas Pelat Datar Dengan Perubahan Bilangan Reynolds. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Energi adalah elemen penting dalam industri, termasuk industri penerbangan yang merupakan salah satu konsumen energi terbesar. Krisis energi global dan dampak lingkungan dari bahan bakar fosil mendorong upaya efisiensi energi melalui optimalisasi aerodinamika pesawat, khususnya dalam mengurangi hambatan aerodinamis (drag) yang diakibatkan oleh separasi aliran pada lapisan batas (boundary layer). Hambatan ini meningkatkan konsumsi bahan bakar dan menurunkan efisiensi sistem, sehingga inovasi seperti boundary layer control (BLC) menjadi solusi penting. Metode BLC seperti penggunaan groove, vortex generator, atau bump berfungsi mengendalikan aliran udara untuk menunda separasi dan meningkatkan efisiensi aliran. Inovasi aerodinamika ini memungkinkan pengurangan konsumsi bahan bakar tanpa menurunkan kualitas performa, sekaligus menjadi langkah strategis dalam mendukung keberlanjutan energi di industri penerbangan. Penelitian ini bermaksud untuk mengetahui pengaruh penambahan triangular bump pada pelat datar dengan variasi sudut bump dan bilangan Reynolds terhadap karakteristik aerodinamika.Penelitian dilakukan secara numerik menggunakan software ANSYS Fluent 2024 R2 dengan metode CFD (Computational Fluid Dynamic). Proses dimulai dengan pembuatan geometri menggunakan Solidworks, kemudian dilanjutkan ke tahap pre-processing yaitu pembuatan mesh dan penentuan boundary condition, kemudian masuk ke tahap processing untuk pengambilan data, dan diakhiri dengan tahap post-processing untuk mengolah serta menganalisis hasil penelitian. Penelitian ini melakukan simulasi numerik aliran pada pelat datar dua dimensi dengan halangan berupa triangular bump dengan panjang alas 4 mm, menggunakan variasi sudut 30°, 45°, dan 60° serta bilangan Reynolds 13000 dan 21000. Analisis dalam penelitian ini dilakukan pada aliran dua dimensi dengan kondisi steady flow, menggunakan turbulence viscous model k-ω SST untuk mengkaji efek penambahan triangular bump terhadap karakteristik aerodinamika pada pelat datar. Penambahan bump menyebabkan terbentuknya bubble separation (separasi lokal) pada permukaan pelat, yang dapat meningkatkan momentum aliran di sekitar lapisan batas (boundary layer). Diperkirakan, semakin besar sudut kemiringan bump mendekati 90°, separation bubble yang terbentuk cenderung lebih tebal dan stabil akibat gradien tekanan yang lebih tajam di sekitar area bump. Meskipun penambahan bump tidak secara langsung mengurangi gaya hambat (drag), keberadaannya dapat memodifikasi struktur aliran dan distribusi tekanan di sekitar permukaan, sehingga tetap memberikan pengaruh terhadap karakteristik aerodinamika sistem secara keseluruhan.Hasil studi numerik menunjukkan bahwa penambahan bump segitiga dengan panjang alas 4 mm pada pelat datar dapat memicu terbentuknya bubble separation dan meningkatkan intensitas turbulensi, terutama di area adverse pressure gradient. Variasi sudut bump 30°, 45°, dan 60° menunjukkan bahwa semakin besar sudut, semakin besar dan stabil separation bubble yang terbentuk. Selain itu, bilangan Reynolds 13000 dan 21000 tidak mempengaruhi ukuran bubble separation secara signifikan. Konfigurasi dengan bump memang menghasilkan nilai koefisien drag yang lebih tinggi dibandingkan pelat polos, namun tetap memberikan pengaruh lokal terhadap distribusi tekanan dan struktur aliran di sekitar pelat.
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Energy is a crucial element in industry, including the aviation sector, which is one of the largest energy consumers. The global energy crisis and the environmental impacts of fossil fuels have driven efforts toward energy efficiency through aerodynamic optimization of aircraft, particularly in reducing aerodynamic drag caused by flow separation in the boundary layer. This type of drag increases fuel consumption and reduces system efficiency, making innovations such as Boundary Layer Control (BLC) essential. BLC methods—such as the use of grooves, vortex generators, or bumps—aim to control airflow to delay flow separation and improve flow efficiency. These aerodynamic innovations enable a reduction in fuel consumption without compromising performance quality, while also serving as strategic steps to support energy sustainability in the aviation industry. This study aims to investigate the effect of adding triangular bumps on a flat plate, with variations in bump angle and Reynolds number, on aerodynamic characteristics. The research was conducted numerically using ANSYS Fluent 2024 R2 software with the Computational Fluid Dynamics (CFD) method. The process began with geometry modeling in SolidWorks, followed by the pre-processing stage, including mesh generation and boundary condition setup. This was continued with the processing stage for data collection, and finally post-processing for data analysis and visualization. Numerical simulations were carried out on a two-dimensional flat plate flow with a triangular bump obstacle featuring a base length of 4 mm. Simulations used bump angle variations of 30°, 45°, and 60°, and Reynolds numbers of 13000 and 21000. The analysis was conducted under steady-state conditions using the k-ω SST turbulence viscous model to examine the effects of triangular bump addition on the aerodynamic characteristics of the flat plate. The addition of a bump induces the formation of a separation bubble (local separation) on the plate surface, which can enhance flow momentum around the boundary layer. It is estimated that as the bump angle approaches 90°, the separation bubble becomes thicker and more stable due to a sharper pressure gradient around the bump area. Although the addition of a bump does not directly reduce drag, its presence can modify the flow structure and pressure distribution around the surface, thus influencing the overall aerodynamic characteristics of the system. Numerical results show that the addition of a triangular bump with a 4 mm base length on a flat plate can trigger the formation of a separation bubble and increase turbulence intensity, especially in areas with an adverse pressure gradient. Bump angle variations of 30°, 45°, and 60° indicate that a larger angle tends to produce a larger and more stable separation bubble. In addition, Reynolds numbers of 13000 and 21000 do not significantly affect the bubble separation size. Although the bump configuration results in a higher drag coefficient compared to the smooth plate, it still provides a localized influence on pressure distribution and flow structure around the plate.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Bump, Pelat Datar, Studi Numerik, Turbulent Boundary Layer, Turbulent Flow, Bump, Flat Plate, Numerical Study, Turbulent Boundary Layer, Turbulent Flow
Subjects:	T Technology > TJ Mechanical engineering and machinery T Technology > TL Motor vehicles. Aeronautics. Astronautics > TL521 Aerodynamics, Hypersonic.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Kanya Aisha Taufik
Date Deposited:	30 Jul 2025 08:45
Last Modified:	30 Jul 2025 08:45
URI:	http://repository.its.ac.id/id/eprint/123699

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