Reduksi Energi Loss Akibat Aliran Sekunder Melalui Penambahan Forward Facing Step Turbulator

Sutrisno, . (2017) Reduksi Energi Loss Akibat Aliran Sekunder Melalui Penambahan Forward Facing Step Turbulator. Doctoral thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Ketika fenomena aliran sekunder telah diketahui mendominasi terjadi kerugian hidrolis, maka para peneliti kembali melakukan penelitian secara fundamental untuk reduksi aliran sekunder. Kejadian aliran sekunder disebabkan akibat ketidak-mampuan aliran viscous dekat bidang tumpu menghadapi adverse pressure. Oleh karena itu salah satu upaya untuk mereduksi aliran sekunder melalui memperkuat energi aliran viscous dekat bidang tumpu dengan penambahan forward facing step turbulent generator(FFST). Analisa penelitian dilakukan dengan cara ekperimen dan simulasi numerik, untuk mendapatkan karateristik aliran sekunder akibat penambahan FFST yang dibandingkan dengan tanpa FFST. Analisa ekperimen yang digunakan dengan teknik oil flow visualization (OFV) pada terowongan angin, yang dihasilkan dalam bentuk goresan skin friction pada permukaan bidang tumpu. Hasil tersebut dipertegas dengan analisa hasil simulasi numerik, yang menggunakan computational fluid dynamic. Hasil simulasi ini memperkuat dan pemberikan informasi lebih lengkap terhadap fenomena aliran sekunder akibat penambahan FFST. Penelitian ini dilakukan pada kondisi aliran free stream Red =2.105 dan Intensitas turbulensi 4%. Model viscous yang digunakan Standard K Epsilon dengan Non Equilibrium Wall Functions, disebabkan karena mesh terdekat dinding memiliki nilai y*=±10. Model dicreatization equation pada setiap parameter digunakan second orde dan criteria convergence 10-5. Hasil penelitian ini dapat mengungkap teori baru tentang reduksi kerugian energi akibat perubahan karakteristik aliran sekunder akibat penambahan FFST di bidang tumpu. Selain itu teori tentang perubahan boundary layer akibat ketebalan FFST (d) terhadap jarak posisi FFST dari Inlet (Lu), yang diamati dalam beberapa posisi didaerah downstream. Penelitian ini akan mengungkap efektifitas FFST terhadap variasi angle of attack dan kelengkungan bodi (camber). =================================================================== hen the secondary flow phenomena is known to dominate the event of hydraulic loss, so the researchers returned to con duct fundamental research for the reduction of secondary flow. Genesis secondary flow caused by the inability of viscous flow to counter adverse pressure. Therefore, a nother to reduce secondary flow through strengthen energy in near wall with the addition of Forward Facing Step - Turbulence Generated (FFST). The research method through experiment and numerical simulations, it aims to determine differences in the characteristics of secondary flow without and with the a ddition of FFST. Experimental method is done with oil flow visualization techniques (O V F) in the wind tunnel that forms scratches skin friction in endwall . The experimental results are reinforced by the results of numerical simulations using computational fluid dynamic,where the results of the simulation is to strengthen and complement the information on the phenomenon of secondary flow due to the addition FFST. Freestream flow conditions in this study used the value Re c = 10 5 and turbulence intensity of 5% , body chord length C=120mm. T he models used viscous Standard K Epsilon with Non Equilibrium Wall Functions. Model dicreatization equation for each parameter used 10 - 5 convergence criteria. T he energy losses presented to the contours axial total pressure coefficient in downstream area . The theory of this research stated that the 3D flow is restricted by ESP. While in the 3D flow, the flow is divided into attachment line and 3D - separation line. Attachment line caused by the flow able to touch the leadin g edge body. Attachment line caused by the flow able to touch the leading edge body. 3D - separation caused by the flow not able to touch the leading edge body , t his flow is limited by the 3D - δ. Result of the addition FFST reduced of secondary flow b etween 10 - 25%, this reduction depend on the shape of the body profile , angle of attack and camber

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: Aliran sekunder, Aliran 3D, Forward facing step, turbulen
Subjects: T Technology > TJ Mechanical engineering and machinery
T Technology > TL Motor vehicles. Aeronautics. Astronautics
Divisions: Faculty of Industrial Technology > Mechanical Engineering > (S3) PhD Theses
Depositing User: Sutrisno Sutrisno
Date Deposited: 07 Nov 2017 03:47
Last Modified: 05 Mar 2019 02:58
URI: http://repository.its.ac.id/id/eprint/48789

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