Studi Numerik Turbin Wells Hidrolik untuk Konversi Energi Gelombang Laut pada Lokasi Berpotensi di Indonesia

Gunawan, Zharfan Ghafara (2024) Studi Numerik Turbin Wells Hidrolik untuk Konversi Energi Gelombang Laut pada Lokasi Berpotensi di Indonesia. Masters thesis, Institut Teknologi Sepuluh Nopember.

Text 6007221020-Master_Thesis.pdf - Accepted Version Restricted to Repository staff only until 1 April 2026. Download (15MB) | Request a copy

Abstract

Peningkatan konsumsi energi yang didominasi oleh energi fosil berdampak pada kenaikan emisi karbon di permukaan bumi. Di sisi lain, Indonesia memiliki beberapa potensi sumber energi terbarukan seperti energi gelombang laut dengan potensi sebesar 17,9 Giga Watt. Namun pemanfaatannya masih sangat sedikit, yaitu hanya 0,3 MW saja atau 0,002% dari total potensi yang ada. Salah satu pengkonversi energi gelombang laut yang telah diaplikasikan di beberapa negara di dunia adalah turbin Wells. Namun turbin Wells sendiri memiliki kekurangan berupa fenomena hysteresis yang menyebabkan penurunan performa saat mendapatkan akselerasi kecepatan fluida. Pada penelitian ini akan dibandingkan performa dan fenomena hysteresis dari turbin Wells konvensional yang beroperasi di udara dan turbin Wells hidrolik yang beroperasi di air laut, serta akan diberikan variasi kecepatan gelombang pada beberapa lokasi berpotensi di Indonesia. Penelitian ini menggunakan metode CFD berbasis Reynold Averaged Navier-Stokes (RANS) dengan model turbulensi k-ω SST. Pemodelan 3D dengan periodic boundary dilakukan dengan kondisi transien untuk memodelkan fenomena hysteresis. Fokus utama dalam penelitian ini adalah mendapatkan data kuantitatif berupa P (daya), T* (torque coefficient) dan η (efisiensi), serta data kualitatif berupa kontur tekanan, kontur kecepatan dan streamline pada turbin Wells. Pengoperasian turbin Wells hidrolik pada air laut diharapkan akan memperbesar momentum sehingga meningkatkan performanya. Serta dengan mengaplikasikan air laut dengan sifat incompressible sebagai fluida kerja, diharapkan akan menghilangkan fenomena hysteresis pada turbin Wells. Hasil simulasi turbin Wells konvensional menunjukkan adanya hysteresis yang disebabkan oleh delay antara kecepatan fluida pada inlet dan kecepatan fluida menuju turbin. Sedangkan hasil perbandingan turbin Wells konvensional dan hidrolik menunjukkan bahwa turbin Wells hidrolik memiliki performa yang lebih baik dengan efisiensi maksimum sebesar 53,2% tanpa adanya fenomena hystersis. Kemudian dari perbandingan 4 hasil simulasi turbin Wells, yaitu turbin Wells konvensional dan hidrolik pada gelombang dengan A = 0,625m dan Tz = 5,5s dan turbin Wells konvensional dan hidrolik pada gelombang dengan A = 0,875m dan Tz = 6,5s, dihasilkan bahwa performa terbaik dimiliki oleh turbin Wells hidrolik pada gelombang dengan A = 0,875m dan Tz = 6,5s dengan efisiensi maksimum sebesar 64,8%.
=================================================================================================================================
Carbon emissions on Earth's surface increase due to rising energy consumption, mostly fossil fuel-driven. On the other hand, Indonesia possesses several promising renewable energy sources, including ocean wave energy, with a 17.9 GW potential. However, its utilization remains very low, at 0.3 MW or 0.002% of total available capacity. One of the ocean wave energy converters applied in several countries is the Wells turbine. However, one of the Wells turbine's drawbacks is the hysteresis phenomenon, which causes a reduction in performance when acquiring airspeed acceleration. In this study, the performance and hysteresis phenomenon of conventional Wells turbines (in air) and hydraulic Wells turbines (in seawater) will be compared, as well as variations in wave velocity at several potential locations in Indonesia. This study applies a CFD method based on Reynolds Averaged Navier-Stokes (RANS) along with a k-ω SST turbulence model. The 3D modeling with periodic boundaries is performed under transient conditions to model the hysteresis phenomenon. The main objective of this research is to collect quantitative data on the Wells turbine in the form of P (power), T* (torque coefficient), and η (efficiency), as well as qualitative data in the form of pressure contours, velocity contours, and streamline. The operation of the hydraulic Wells turbine in seawater is expected to increase its momentum and performance. It is additionally predicted that by using incompressible seawater as the working fluid, the hysteresis phenomenon in the Wells turbine will be eliminated. The simulation results of a conventional Wells turbine showed that hysteresis exists due to the delay between the fluid velocity at the inlet and the fluid velocity onto the turbine. Meanwhile, the comparison results between conventional and hydraulic Wells turbines show that the hydraulic Wells turbine performed better, with a maximum efficiency of 53.2% without the hysteresis phenomenon. Then, a comparison of four Wells turbine simulation results, namely conventional and hydraulic Wells turbines on waves with A = 0.625m and Tz = 5.5s and conventional and hydraulic Wells turbines on waves with A = 0.875m and Tz = 6.5s, revealed that the hydraulic Wells turbine has the best performance at waves with A = 0.875m and Tz = 6.5s, with a maximum efficiency of 64.8%.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	energi terbarukan, gelombang laut, turbin Wells, hysteresis, CFD, renewable energy, ocean waves, Wells turbines, hysteresis,
Subjects:	T Technology > TJ Mechanical engineering and machinery > TJ808 Renewable energy sources. Energy harvesting. T Technology > TJ Mechanical engineering and machinery > TJ870 Hydraulic turbines.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	Zharfan Ghafara Gunawan
Date Deposited:	12 Feb 2024 09:01
Last Modified:	12 Feb 2024 09:01
URI:	http://repository.its.ac.id/id/eprint/106960

Actions (login required)

View Item