Numerical Study of the Effect of Block and Domed Block Bump Width Variation on Flow Characteristics over a Flat Plate With Variying Reynolds Numbers

Fadhilah, Muhammad Irfan (2026) Numerical Study of the Effect of Block and Domed Block Bump Width Variation on Flow Characteristics over a Flat Plate With Variying Reynolds Numbers. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Peningkatan efisiensi aerodinamika merupakan salah satu upaya untuk mengurangi gaya hambat (drag) dan meningkatkan performa aliran pada berbagai aplikasi teknik. Salah satu metode passive flow control yang dapat diterapkan adalah modifikasi geometri permukaan menggunakan bump untuk mengendalikan perkembangan lapisan batas (boundary layer). Penelitian ini bertujuan untuk menganalisis pengaruh geometri Block Bump dan Domed Block Bump dengan variasi lebar 21 mm dan 42 mm terhadap karakteristik aliran di atas pelat datar pada bilangan Reynolds 13.000 dan 21.000. Penelitian dilakukan menggunakan simulasi numerik dua dimensi (two-dimensional Computational Fluid Dynamics) dengan perangkat lunak ANSYS Fluent. Analisis difokuskan pada distribusi pressure coefficient (Cp), drag coefficient (Cd), velocity profile, boundary layer shape factor, dan recirculation bubble untuk mengevaluasi pengaruh geometri bump terhadap perkembangan lapisan batas dan karakteristik aliran. Hasil simulasi menunjukkan bahwa penambahan bump secara signifikan mengubah distribusi tekanan, perkembangan lapisan batas, dan pembentukan daerah resirkulasi dibandingkan dengan pelat datar tanpa bump. Dibandingkan dengan Block Bump, Domed Block Bump menghasilkan distribusi tekanan yang lebih halus, pressure recovery yang lebih baik, daerah separasi yang lebih kecil, serta koefisien hambat total yang lebih rendah. Secara umum, peningkatan lebar bump dari 21 mm menjadi 42 mm meningkatkan karakteristik aerodinamika dengan mengurangi adverse pressure gradient dan memperkecil wake region. Di antara seluruh konfigurasi yang diteliti, Domed Block Bump dengan lebar 42 mm memberikan performa aerodinamika terbaik dengan menghasilkan koefisien hambat total terendah dan recirculation bubble terkecil. Sementara itu, pengaruh peningkatan bilangan Reynolds dari 13.000 menjadi 21.000 relatif lebih kecil dibandingkan pengaruh geometri bump, meskipun beberapa parameter menunjukkan perubahan yang bergantung pada konfigurasi bump. vi Hasil penelitian menunjukkan bahwa optimasi geometri bump, khususnya penggunaan Domed Block Bump dengan lebar 42 mm, merupakan strategi Boundary Layer Control (BLC) pasif yang efektif untuk meningkatkan karakteristik aliran dan mengurangi hambatan aerodinamika.
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Improving aerodynamic efficiency is one of the primary approaches to reducing drag and enhancing flow performance in engineering applications. One passive flow control technique is the modification of surface geometry using bumps to influence boundary-layer development. This study investigates the effects of Block Bump and Domed Block Bump geometries with widths of 21 mm and 42 mm on the flow characteristics over a flat plate at Reynolds numbers of 13,000 and 21,000. A two-dimensional Computational Fluid Dynamics (CFD) simulation was conducted using ANSYS Fluent. The analysis focused on the pressure coefficient (Cp), drag coefficient (Cd), velocity profile, boundary-layer shape factor, and recirculation bubble to evaluate the influence of bump geometry on boundary-layer development and aerodynamic performance. The simulation results show that the addition of surface-mounted bumps significantly modifies the pressure distribution, boundary-layer development, and recirculation region compared with a smooth flat plate. Compared with the Block Bump, the Domed Block Bump produces a smoother pressure distribution, better pressure recovery, smaller separation regions, and lower total drag coefficients. In general, increasing the bump width from 21 mm to 42 mm improves the aerodynamic characteristics by reducing the adverse pressure gradient and minimizing the wake region. Among all investigated configurations, the 42 mm Domed Block Bump demonstrates the best overall aerodynamic performance by producing the lowest total drag coefficient and the smallest recirculation bubble. Meanwhile, the influence of increasing the Reynolds number from 13,000 to 21,000 is secondary compared with the influence of bump geometry, although several flow parameters exhibit geometry-dependent variations. The results demonstrate that optimizing bump geometry, particularly through the use of a 42 mm Domed Block Bump, is an effective passive Boundary Layer Control (BLC) strategy for improving flow characteristics and reducing aerodynamic drag.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Boundary Layer Control, Computational Fluid Dynamics, Drag Coefficient, Domed Block Bump, Flat Plate.
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:	Muhammad Irfan Fadhilah
Date Deposited:	31 Jul 2026 07:48
Last Modified:	03 Aug 2026 17:47
URI:	http://repository.its.ac.id/id/eprint/141782

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