Soesilo, Matthew (2026) Studi Eksperimental Aliran Melintasi Silinder Sirkular Tunggal dengan Penempatan Plat Splitter pada Bagian Upstream “Studi Kasus Pengaruh Panjang dan Ketebalan Plat Splitter”. Other thesis, Institut Teknologi Sepuluh Nopember.
![[thumbnail of 5007221064-Undergraduate_Thesis.pdf]](http://repository.its.ac.id/style/images/fileicons/text.png) |
Text
5007221064-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (2MB) | Request a copy |
Abstract
Fenomena aliran fluida yang melintasi bluff body seperti silinder sirkular menghasilkan gaya hambat (drag) yang signifikan akibat terjadinya separasi aliran dini dan pembentukan daerah wake yang lebar di bagian hilir. Salah satu metode passive flow control yang banyak diteliti untuk mengurangi gaya hambat tersebut adalah penggunaan splitter plate, yaitu pelat datar yang dipasang di sekitar silinder untuk memodifikasi struktur wake dan menekan intensitas pusaran (vortex shedding). Penelitian ini bertujuan untuk menganalisis pengaruh variasi panjang dan ketebalan splitter plate terhadap distribusi koefisien tekanan (Cp), koefisien gaya hambat tekanan (C_dp), serta profil kecepatan di daerah wake silinder sirkular. Eksperimen dilakukan menggunakan open-circuit subsonic wind tunnel di Laboratorium Mekanika Fluida Departemen Teknik Mesin FTIRS–ITS dengan kecepatan aliran udara 10 m/s. Benda uji berupa silinder akrilik berdiameter 36 mm dan panjang 200 mm, yang dipasangi splitter plate dengan variasi panjang (L = 0,5D, 1,5D, dan 2,0D) serta ketebalan (t = 0,08D dan 0,14D). Jarak celah antara silinder dan splitter plate dijaga konstan sebesar 5 mm. Pengukuran tekanan dilakukan menggunakan wall pressure tap dan inclined manometer, sedangkan profil kecepatan diukur menggunakan pitot-static tube pada jarak 4D dari pusat silinder. Hasil eksperimen menunjukkan bahwa penambahan splitter plate mampu mereduksi gaya hambat tekanan secara signifikan dengan memodifikasi struktur wake di belakang silinder. Pada silinder tanpa splitter, koefisien gaya hambat tekanan berada pada nilai tinggi akibat separasi dini dan tekanan dasar yang rendah. Peningkatan panjang splitter plate hingga L/D = 1.5 memberikan efek paling optimal, ditandai dengan peningkatan tekanan dasar pada sudut θ = 180° serta penurunan nilai Cdp hingga sekitar 18% untuk ketebalan t = 5 mm dibandingkan silinder polos. Splitter plate dengan panjang lebih pendek menghasilkan reduksi drag yang lebih terbatas, sedangkan penambahan panjang hingga L/D = 2.0 tidak memberikan peningkatan kinerja yang signifikan akibat meningkatnya rugi viskos aliran. Dengan demikian, konfigurasi splitter plate L/D = 1.5 dan t = 5 mm diidentifikasi sebagai kondisi optimum untuk reduksi gaya hambat tekanan pada silinder sirkular.
======================================================================================================================================
The flow of fluid past a bluff body such as a circular cylinder generates significant drag due to early flow separation and the formation of a wide wake region downstream. One of the widely studied passive flow control methods to reduce this drag is the use of a splitter plate — a flat plate installed around the cylinder to modify the wake structure and suppress vortex shedding intensity. This study aims to analyze the effect of varying splitter plate length and thickness on the distribution of pressure coefficient (Cp), drag pressure coefficient (Cdp), and velocity profile in the wake region of a circular cylinder. The experiment was conducted using an open-circuit subsonic wind tunnel at the Fluid Mechanics Laboratory, Department of Mechanical Engineering, FTIRS–ITS, with a freestream velocity of 10 m/s. The test model consists of an acrylic circular cylinder with a diameter of 36 mm and a span of 200 mm, equipped with splitter plates of varying lengths (L = 0.5D, 1.0D, 1.5D, and 2.0D) and thicknesses (t = 0.08D and 0.14D). The gap distance between the cylinder and the splitter plate was kept constant at 5 mm. Pressure measurements were carried out using wall pressure taps and an inclined manometer, while the velocity profiles were obtained using a Pitot-static tube positioned 4D downstream from the cylinder’s center. The experimental results show that the addition of a splitter plate is able to significantly reduce pressure drag by modifying the wake structure behind the cylinder. For the bare cylinder, the pressure drag coefficient remains high due to early flow separation and low base pressure. Increasing the splitter plate length to L/D = 1.5 produces the most optimal effect, as indicated by an increase in base pressure at θ = 180° and a reduction in the pressure drag coefficient of up to approximately 18% for a plate thickness of t = 5 mm compared to the smooth cylinder. Shorter splitter plates result in more limited drag reduction, while further increasing the splitter plate length to L/D = 2.0 does not yield additional performance improvement due to increased viscous flow losses. Therefore, a splitter plate configuration with L/D = 1.5 and t = 5 mm is identified as the optimum condition for pressure drag reduction on a circular cylinder.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | Silinder sirkular, splitter plate, wake, coefficient of pressure (Cp), coefficient of drag pressure (C_dp), passive flow control, Circular cylinder, splitter plate, wake, coefficient of pressure (Cp), coefficient of drag pressure (Cdp), passive flow control. |
| 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: | Matthew Soesilo |
| Date Deposited: | 03 Feb 2026 01:05 |
| Last Modified: | 03 Feb 2026 01:05 |
| URI: | http://repository.its.ac.id/id/eprint/131703 |
Actions (login required)
 |
View Item |