STUDI NUMERIK OPTIMASI POSISI VORTEX GENERATOR GUNA MEREDUKSI ALIRAN SEKUNDER DEKAT ENDWALL PADA AIRFOIL BRITISH 9C7/32.5C50

ANDRYANTO, ARISTO (2016) STUDI NUMERIK OPTIMASI POSISI VORTEX GENERATOR GUNA MEREDUKSI ALIRAN SEKUNDER DEKAT ENDWALL PADA AIRFOIL BRITISH 9C7/32.5C50. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Aliran fluida ketika melintasi suatu airfoil dekat end wall akan terjadi aliran sekunder. Beberapa modifikasi bertujuan untuk mereduksi aliran sekunder yang terjadi diantara airfoil dan endwall dengan penambahan vortex generator telah dilakukan. Pada penelitian ini akan dikaji tentang optimasi penempatan vortex generator pada airfoil. Penambahan dan variasi penempatan vortex generator yang dipasang pada airfoil di dekat endwall bertujuan untuk menentukan posisi yang paling optimal yang dapat mengarahkan aliran dekat endwall, sehingga aliran sekunder dapat tereduksi. Penelitian ini dilakukan dengan simulasi numerik. Model benda uji berupa airfoil British 9C7/32.5C50 yang terpasang pada endwall yang berbentuk pelat datar. Penambahan vortex generator di dekat endwall dengan jarak YVG = 4%C dan sudut (β)=14. Variasi jarak vortex generator terhadap leading edge yaitu XVG = 40%C, 45%C dan 50%C. sedangkan angle of attack diatur tetap (α = 12°). Bilangan Reynolds yang digunakan adalah Rec = 1.14x105 Pemodelan numerik dilakukan mengunakan software Gambit 2.4 dan Fluent 6.3.26 dengan model 3ddp steady turbulent viscous standard k-epsilon (SKE). Hasil penelitian diketahui bahwa penambahan vortex generator pada upper surface dari airfoil dapat meningkatkan intensitas turbulensi aliran. Sehingga separasi 3 dimensi yang terjadi di upper surface airfoil dekat endwall dapat ditunda dan effective area semakin bertambah luas. Hal ini dapat mereduksi kerugian energi yang membuat koefisien lift (CL) meingkat, koefisien drag (CL) menurun dan total pressure losses coefficient (ζ) menurun. Pereduksian energi paling optimal didapatkan dengan menempatkan vortex generator pada posisi 45%C dari leading edge, dengan peningkatan CL sebesar 3,67%, penurunan CD sebesar 2,7% dan penurunan ζ sebesar 9,3%. "=============================================================================================" When fluid flow across an airfoil near endwall, a secondary flow will occur. Some modifications aim to reduce secondary flow that occurs between the airfoil and endwall with the addition of vortex generators have been done. This research will assessed on position optimization of vortex generators on the airfoil. Additions and variations in the placement of vortex generators mounted on the airfoil near the endwall aims to determine the most optimal position which can direct the flow near the endwall, so that the secondary flow can be reduced. This research was conducted by numerical simulations. Model test objects, airfoil British 9C7 / 32.5C50, is mounted on a flat plate-shaped endwall. The addition of vortex generators near endwall with ZVG = 0,04C distance and the angle of 14 °. Distance variation of the leading edge vortex generator is XVG = 0,4C, 0,45C and 0,5C. while the angle of attack is fixed at 12°. Reynolds number used was 114.000. Numerical modeling is done using software Gambit 2.4 and Fluent 3.6.26 with 3ddp model and steady turbulent viscous standard k-epsilon (SKE). The survey results revealed that the addition of vortex generators on the upper surface of the airfoil may increase the turbulence intensity. So the 3 dimensional separation that occurs in the upper surface of the airfoil near the endwall may be delayed and increases the size of effective area. This phenomenon can reduce energy losses that reduces lift coefficient, decreases drag coefficient and decreases the total pressure losses coefficient. The most optimal energy reduction is obtained by placing a vortex generator on 0,45C position from the leading edge, with an increase in the lift coefficient of 3.67 percent, a decrease in drag coefficient of 2.7 percent and a reduction in total pressure losses coefficient of 9.3 percent.

Item Type: Thesis (Undergraduate)
Additional Information: RSM 629.134 32 And s
Uncontrolled Keywords: airfoil British 9C7/32.5C50 , endwall, vortex generator,
Subjects: T Technology > TJ Mechanical engineering and machinery > TJ164 Power plants--Design and construction
Divisions: Faculty of Industrial Technology > Mechanical Engineering > (S1) Undergraduate Theses
Depositing User: Users 13 not found.
Date Deposited: 09 Jan 2017 04:02
Last Modified: 26 Dec 2018 03:14
URI: http://repository.its.ac.id/id/eprint/1393

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