Studi Eksperimental Lift Yang Berfluktuasi Pada Silinder Akibat Vortex Shedding

Sivilianto, Hendri (2007) Studi Eksperimental Lift Yang Berfluktuasi Pada Silinder Akibat Vortex Shedding. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pada sebuah profil silinder yang dialiri fluida dengan kecepatan tertentu, akan menghasilkan gaya hambat (drag), dan gaya angkat (lift). Profil silinder diduga akan mengalami osilasi jika pada silinder ini diberikan aliran. Pengetahuan mengenai osilasi yang diakibatkan vortex shedding sangat diperlukan untuk mendesain konstruksi yang optimal. Dalam penelitian kali ini dipergunakan silinder dengan UD konstan = 3, 7 (D = 2, 4, dan 6 em) dipasang tegak lurus terikat pada ujung bawah pegas batang, dim ana ujung alas peg as batang diikat pada dinding alas di dalam terowongan angin. Untuk mendeteksi getaran pada silinder maka dibagian bawah silinder dipasang plat tipis yang cukup kaku, dan plat ini dipasang menembus dinding bawah wind tunnel. Pegas batang yang digunakan memiliki fleksibilitas cukup untuk membuat silinder tersebut bergerak bebas menyamping (horizontal) saat dikenai aliran fluida. Pengukuran displacement (pergeseran) plat dilakukan dengan magnetic approximate yang diletakkan disamping ujung bawah plat. Penelitian ini dilakukan pada sebuah terowongan angin (wind tunnel) pada bilangan Reynolds (Re) = (1- 4,3) x 104. Osilasi akibat vortex shedding menunjukkan bilangan Strouhal (St) relatif konstan pada Re yang digunakan. Displacement and koefisien lift mengalami fluktuasi pada tiap harga Re. Hasil eksperimen menguatkan adanya fase frekuensi transisi pada dimensi tertentu
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In a cylindrical profile flowing with fluid at a certain speed, it will produce drag and lift forces. The cylindrical profile is expected to experience oscillations if the cylinder is given flow. Knowledge of oscillations caused by vortex shedding is essential for designing optimal construction. In this study, cylinders with constant UD = 3, 7 (D = 2, 4, and 6 em) were used, mounted perpendicularly attached to the lower end of the rod spring, where the base end of the rod peg was attached to the base wall inside the wind tunnel. To detect vibrations in the cylinder, a thin, rigid plate was installed at the bottom of the cylinder, and this plate was installed through the bottom wall of the wind tunnel. The rod spring used has sufficient flexibility to make the cylinder move freely sideways (horizontally) when subjected to fluid flow. Measurement of plate displacement was carried out with a magnetic approximator placed next to the bottom end of the plate. This research was conducted in a wind tunnel at Reynolds number (Re) = (1-4.3) x 104. Oscillations due to vortex shedding showed a relatively constant Strouhal number (St) at the Re used. Displacement and lift coefficients fluctuated at each Re value. The experimental results confirmed the existence of a phase frequency transition at certain dimensions

Item Type:	Thesis (Other)
Additional Information:	RSM 620.106 Siv s-1 2007 (weeding)
Uncontrolled Keywords:	Bilangan Reynolds, bilangan Strouhal, silinder sirkular, lift unsteady; Reynolds number, Strouhal number, circular cylinder, unsteady lift
Subjects:	Q Science > QC Physics > QC151 Fluid dynamics
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	EKO BUDI RAHARJO
Date Deposited:	01 Dec 2025 06:12
Last Modified:	01 Dec 2025 06:12
URI:	http://repository.its.ac.id/id/eprint/128843

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