Studi Pemilihan Model Turbulen Pada Vertical Axis Water Turbine (VAWT) Tipe Gorlov Menggunakan Metode Computational Fluid Dynamics (CFD).

Fridayana, Elyas Nur (2022) Studi Pemilihan Model Turbulen Pada Vertical Axis Water Turbine (VAWT) Tipe Gorlov Menggunakan Metode Computational Fluid Dynamics (CFD). Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Wilayah Indonesia bagian Timur yang berupa kepulauan menyimpan potensi energi arus laut sangat besar. Vertikal Axis Water Turbine (VAWT) tipe
Gorlov menjadi teknologi yang cocok untuk diterapkan di daerah tersebut. Sudu turbin ini mempunyai bentuk helikal yang memberikan keuntungan dalam minimalisasi fluktuasi torsi. Akan tetapi, aliran spanwise menjadi sering muncul sebagai konsekuensi bentuk helikal tersebut. Computational Fluid Dynamics (CFD) sangat populer digunakan untuk memprediksi kinerja turbin VAWT termasuk tipe Gorlov. Persamaan Reynolds Averaged Navier-Stokes (RANS) muncul guna memperingan pekerjaan CFD. Efek fluktuasi aliran turbulen dimodelkan melalui viskositas eddy sesuai hipotesis Boussinesq dengan asumsi isotropik. Prosedur perhitungan viskositas eddy dikenal sebagai model turbulen. Metode ini hanya akurat pada kasus tertentu saja. Sehingga perlu dicari model turbulen yang handal untuk memprediksi kinerja turbin Gorlov. Dimana kinerja turbin sangat dipengaruhi oleh fenomena dynamic stall. Data eksperimen sekunder berupa kurva efisiensi turbin Gorlov dimanfaatkan untuk memvalidasi hasil simulasi CFD. Model 3-dimensi disimulasikan dengan memanfaatkan Spalart-Allmaras, k- -kl- - RNG yang mewakili model turbulen transisi serta non-transisi. Studi independensi mesh dilakukan guna mencari jumlah elemen optimal. Nilai y+ kurang dari 1 diaplikasikan untuk memastikan aliran dekat dinding terselesaikan pada daerah viscous sub layer. Perputaran turbin dimodelkan melalui teknik sliding mesh dengan pertambahan sudut putar 2 derajat. Perbedaan kecepatan putar turbin mempengaruhi karakteristik kurva efisiensi tiap model turbulen. Pada putaran rendah, k- nderung overpredicts sedangkan model turbulen lainya underpredicts. Seiring meningkatnya kecepatan putar, semua model turbulen memberi hasil dibawah eksperimen kecuali k-kl- akurat. Akurasi tersebut disebabkan karena k-kl- tegangan geser dinding yang diproduksi turbin saat terjadi aliran spanwise.
=================================================================================================================================== The need for petroleum in daily life is The Eastern part of Indonesia is an archipelago that has a huge potential as a source of ocean current energy. The Vertical Axis Water Turbine (VAWT) Gorlov type is a suitable technology to be used in this area. The turbine blades have a helical shape that aids to minimise torque fluctuations. However, spanwise flow keeps occurring due to the helical shape. The Computational Fluid Dynamics (CFD) is popularly used to predict the performance of VAWT including the Gorlov type. Reynolds Averaged Navier- Stokes (RANS) equations appear to ease computational effort of the CFD. The effect of the fluctuation turbulence flow is modelled by eddy viscosity in line with Boussinesq hypothesis using isotopic assumption. The procedure to calculate viscosity eddy is known as turbulence model. However, as this method is only accurate in certain cases, it is necessary to find a turbulence model that is effective in predicting the performance of the Gorlov turbine. The performance of the turbine is highly influenced by the phenomenon of dynamic stall. The efficiency curve of the Gorlov turbine from the secondary experiment data utilised to validate the results of the CFD simulation. The 3D model is simulated using Spalart-Allmaras, k- -kl- - both turbulence models with and without transition. Independent mesh study was carried out to find the amount of the optimal element. The y+ value lesser than 1 is applied to ensure the near wall flow is resolved to the viscous sublayer region. The turbine rotation is modelled using sliding mesh technique with a rotation increment angle by 2 degrees. The difference in the turbine rotating speed affects the efficiency curve characteristic of every turbulent model. In low rotation speed, the k- In line with the increase in the rotation speed, all turbine models give results under
experiment except k-kl- -klspanwise flow.

Item Type:	Thesis (Other)
Additional Information:	RTKe 532.052 7 Fri s-1 2022
Uncontrolled Keywords:	CFD, gorlov, model turbulen, viskositas eddy. CFD, eddy viscosity, gorlov, turbulence model.
Divisions:	Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis
Depositing User:	Mr. Marsudiyana -
Date Deposited:	22 May 2026 08:21
Last Modified:	22 May 2026 08:21
URI:	http://repository.its.ac.id/id/eprint/133361

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