Studi Numerik Karakteristik Boundary Layer Turbulen Pada Pelat Datar Dengan Alur Melintang Tipe -D

Whindracaya, Ardiansyah Arya Mahendra (2016) Studi Numerik Karakteristik Boundary Layer Turbulen Pada Pelat Datar Dengan Alur Melintang Tipe -D. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Boundary layer akan terbentuk apabila aliran viscous melewati suatu kontur permukaan. Hal ini menyebabkan terjadinya gaya drag di kontur permukaan, oleh karena itu boundary layer yang terbentuk perlu dikontrol. Salah satu cara untuk mengkontrol boundary layer yang terbentuk adalah dengan memberi alur permukaan yang dilalui aliran. Pada penelitian ini, aliran yang dikaji adalah aliran boundary layer turbulen yang melintasi suatu pelat datar dengan alur melintang tipe-D. Alur tipe-D adalah tipe alur berbentuk persegi dengan kedalaman dan jarak antar alur yang sama, diletakan normal terhadap arah aliran. Penelitian ini dilakukan secara simulasi numerik. Terdapat 4 model yang disimulasikan yaitu pelat datar (smooth-wall), pelat beralur tipe-D ukuran 4mm, 10mm, dan 30mm . Bilangan Reynolds berdasarkan panjang pelat yaitu Rel = 2.16 x 106 dan kecepatan freestream pada inlet sebesar 10 m/s. Pemodelan numerik dilakukan menggunakan software Gambit 2.4.6 dan Fluent 6.3.26 dengan model 2ddp unsteady, viscous model standart k-epsilon. Berdasarkan hasil penelitian, penambahan alur tipe-D berbagai ukuran meningkatkan koefisien drag total dibanding pelat datar (smooth-wall). Pressuregradient yang terbentuk didalam alur berkontribusi pada peningkatan ini walaupun nilai koefisien skin-friction mengalami penurunan. Tidak hanya koefisien drag total, tapi nilai intensitas turbulensi juga mengalami peningkatan dibanding pelat datar (smooth-wall). Didalam alur juga terbentuk vortex yang berkontribusi dalam penurunan koefisien skin-friction. ================================================================================================================== Boundary layer is formed when viscous fluid flow over a surface. Boundary layer causes the drag force, therefore the boundary layer should be controlled. One of treatment to control boundary layer formation is to modify the flat plate with transverse grooves. This research discusses turbulent boundary layer of flow over a flat plate with d-type transverse grooves. D-type groove is type of groove characterized by square-groove with equal-depth and equal-space within grooves, places normal to flow direction. The research was conducted using numerical simulation. There are 4 models used for this research, which are flat plate without groove, flat plate with d-type in different sizes, 4mm, 10mm, and 30mm. Reynolds number based on plate length was determined at Rel = 2.16 x 106 and freestream velocity of 10 m/s. The numerical modeling was performed using software gambit 2.4.6 and fluent 6.3.26 model 3ddp unsteady, turbulent viscous standart k-epsilon. According to this research, modifying the flat plate with various sizes of dtype groove (4mm, 10mm, and 30mm), caused increasing of total drag coefficient compared to flat plate (smooth-wall). Pressure-gradient at the grooves contributed to the increasing of drag force, eventhough skin-friction coefficient along the wall decreasing than flat plate (smooth-wall). Not only total drag coefficient, but also the turbulence intensity has increased compared to flat plate (smooth-wall). Besides of that, a vortex formed inside the groove contributes to skin-friction coefficient reduction.

Item Type: Thesis (Undergraduate)
Additional Information: RSM 620.106 4 Whi s
Uncontrolled Keywords: Sistem kendali, longitudinal, lateral direksional, Fixed-wing UAV,Control system, longitudinal motion, Lateral direction Motion Fixed-Wing UAV
Subjects: Q Science > QA Mathematics > QA911 Fluid dynamics. Hydrodynamics
Divisions: Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User: ansi aflacha
Date Deposited: 22 Jun 2020 01:59
Last Modified: 22 Jun 2020 01:59
URI: http://repository.its.ac.id/id/eprint/76191

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