Studi Eksperimen Pengaruh Penggunaan Inlet Disturbance Body Terhadap Karakteristik Aliran Melintasi Empat Buah Silinder Sirkular Yang Tersusun In-Line Square “ Studi Kasus Rasio Jarak Antar Silinder 1.5≤L/D≤2.5 Pada Sudut Pengganggu 30° Dan 60° ”

Muhammad, Herdi (2014) Studi Eksperimen Pengaruh Penggunaan Inlet Disturbance Body Terhadap Karakteristik Aliran Melintasi Empat Buah Silinder Sirkular Yang Tersusun In-Line Square “ Studi Kasus Rasio Jarak Antar Silinder 1.5≤L/D≤2.5 Pada Sudut Pengganggu 30° Dan 60° ”. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penelitian ini adalah untuk mendapatkan informasi mengenai fenomena evolusi
aliran dari momentum fluida yang attachment pada kontur permukaan benda
lengkung seperti silinder sirkular. Karakteristik yang diperoleh sangat bermanfaat
dalam memprediksi gaya-gaya aerodinamik pada silinder sirkular, terutama yang
berkenaan dengan reduksi gaya hambat (drag reduction). Untuk mereduksi gaya
drag dengan cara menambahkan bodi pengganggu di daerah upstream, modifikasi
geometri, dan meningkatkan kekasaran permukaan. Karakteristik aliran yang
melintasi silinder sirkular susunan in-line square dengan tambahan bodi
pengganggu ini diteliti secara eksperimental pada open circuit subsonic wind
tunnel, Laboratorium Mekanika Mesin Fluida ITS Surabaya.
Riset ini dilakukan secara eksperimental, dimana benda uji yang digunakan
berupa empat buah silinder sirkular (main bluff body) berdiameter (D) 25 mm
dengan susunan in-line square. Variasi jarak antar silinder L/D 1.5; 2; dan 2.5,
silinder pengganggu berdiameter (d) 4 mm dengan gap (δ) 0.4 mm dari
permukaan silinder upstream pada sudut stagger (α) 300 dan 600 serta pada
bilangan Reynolds 2.2 x104.
Hasil eksperimen menunjukkan bahwa dengan adanya penambahan empat buah
inlet disturbance body pada sudut stagger 300 dan dibandingkan dengan tanpa
bodi pengganggu pada rasio jarak L/D = 2, terjadi fenomena reattachment pada
silinder sirkular. Fenomena reattacthment tersebut menyebabkan separasi aliran
lebih tertunda. Tertundanya separasi aliran diindikasikan dengan nilai koefisien
drag jauh lebih kecil. Reduksi koefisien drag pressure (CDP) paling efektif pada
silinder sirkular terjadi pada penambahan bodi pengganggu α = 300, adapun
reduksi koefisien drag pressure yang diperoleh masing-masing silinder 1=1.088,
silinder 2 = 0.859, silinder 3 = - 0.313 dan silinder 4 = 0.309.

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This study is to obtain information about the evolution of the phenomenon of
momentum fluid flow attachment to the curved contour of the surface objects such
as circular cylinder. Acquired characteristics are very helpful in predicting the
aerodynamic forces on a circular cylinder, especially with regard to drag reduction
(drag reduction). To reduce the drag force by inlet disturbance body in the
upstream area, geometry modification, and increase the surface roughness. Flow
characteristics across the circular cylinder in-line square arrangement with
additional inlet disturbance body is investigated experimentally in an open circuit
subsonic wind tunnel, Laboratory of Fluid Mechanics Engineering ITS Surabaya.
This research was carried out experimentally, where the test object is used in the
form of four circular cylinder (main bluff body) the diameter of circular cylinder
(D) 25 mm with an in-line square arrangement. Variation distance between the
cylinder L / D 1.5; 2; and 2.5, the diameter inlet disturbance body (d) 4 mm with a
gap (δ) of 0.4 mm from the surface upstream cylinder at a stagger angle (α) of 300
and 600 as well as the Reynolds number 2.2 x104.
The experimental results show that with the addition of four body inlet
disturbance at a stagger angle of 300 and compared to the body without
confounding the spacing ratio L/D = 2, occurs at the reattachment phenomenon
circular cylinder. Reattachment phenomenon causes flow separation is delayed.
The delay of flow separation is indicated by the value of the drag coefficient is
much smaller. Reduction of pressure drag coefficient (CDP) most effective in
circular cylinder occurs on the inlet disturbance body at stagger α = 300, while the
reduction of pressure drag coefficient obtained each cylinder 1 = 1088, cylinders 2
= 0859, cylinder 3 = - 0.313 and cylinder 4 = 0309.

Item Type:	Thesis (Masters)
Additional Information:	RTM 620.106 4 Muh s
Uncontrolled Keywords:	Empat silinder sirkular; susunan in-line; koefisien drag; inlet disturbance body; Four circular cylinder; in-line square arrangement; drag coefficient
Subjects:	T Technology > TJ Mechanical engineering and machinery
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	Anis Wulandari
Date Deposited:	31 May 2017 06:24
Last Modified:	27 Dec 2017 02:56
URI:	http://repository.its.ac.id/id/eprint/41448

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