Uji Model Fisik Hidraulik Perilaku Aliran Pada Fishway Tipe Pool Passes

Nurhayati, Dyan Eka (2019) Uji Model Fisik Hidraulik Perilaku Aliran Pada Fishway Tipe Pool Passes. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Fishway merupakan bangunan pelengkap pada bangunan melintang sungai yang berfungsi sebagai jalur migrasi ikan. Faktor utama yang menentukan keberhasilan fungsi fishway adalah kecepatan aliran. Kecepatan aliran pada fishway tidak boleh melebihi kecepatan berenang ikan berukuran terkecil yang akan melintasinya. Fishway tipe teknis merupakan tipe fishway yang paling sering digunakan, salah satunya adalah pool passes dengan free flow orifice dan submerged orificial. Kecepatan aliran pada pool passes masih dapat memiliki nilai yang lebih besar dibandingkan dengan kecepatan berenang ikan. Hal ini dibuktikan dengan adanya beberapa fishway yang tidak mampu berfungsi secara optimal karena ikan menolak untuk berenang melaluinya. Oleh karena itu, dilakukan penelitian mengenai pola kecepatan aliran pada fishway pool passes. Pada penelitian ini dilakukan pemodelan beberapa variasi pool passes untuk mengurangi kecepatan aliran sekaligus mengarahkan aliran di dalam kolam fishway. Variasi yang digunakan meliputi debit aliran dan penambahan model dilakukan menggunakan alat Acoustic Doppler Velocimeter (ADV). Berdasarkan hasil analisis pada kolam 4 dan kolam 10, pola distribusi kecepatan aliran untuk model 1 menunjukkan bahwa kecepatan minimum sebesar 0–0,2 m/det hanya terjadi di bagian tengah kolam. Sementara itu, pada model 2 dan model 3, kecepatan minimum terjadi di sisi kolam yang berdekatan dengan dinding fishway. Untuk kecepatan aliran pada submerged orifice, di kolam 4 diperoleh kecepatan sebesar 1,25–0,89 m/det pada model 1, 0,99–0,77 m/det pada model 2, dan 0,70–0,40 m/det pada model 3. Sedangkan pada kolam 10, kecepatan aliran untuk model 1 sebesar 1,17–0,94 m/det, model 2 sebesar 1,08–0,89 m/det, dan model 3 sebesar 0,70–0,44 m/det. Berdasarkan hasil tersebut dapat disimpulkan bahwa baffle efektif sebagai pengarah aliran di dalam kolam fishway sekaligus mampu mengurangi kecepatan aliran pada submerged orifice. Dengan demikian, model 3 yang menggunakan dua buah baffle memberikan hasil yang lebih baik dibandingkan model asli pool passes (model 1).
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The fishway, also known as a fish ladder, is a complementary structure installed at river-crossing hydraulic structures to provide a migration route for fish. The primary factor determining the effectiveness of a fishway is the flow velocity. The flow velocity within a fishway must not exceed the swimming speed of the smallest fish species expected to pass through it. Among the technical fishway designs, the pool pass with free-flow orifice and submerged orifice is one of the most commonly used types. However, the flow velocity within pool passes may still exceed the swimming capability of fish. This has been demonstrated by several fishways that failed to function effectively because fish refused to swim through them. Therefore, this study was conducted to investigate the flow velocity distribution in pool pass fishways. In this study, several pool pass models were developed to reduce flow velocity and guide the flow within the fishway pool. The investigated variables were discharge and the addition of baffles. Flow velocity for each model was measured using an **Acoustic Doppler Velocimeter (ADV). Based on the analysis of pools 4 and 10, the flow velocity distribution for model 1 showed a minimum velocity of 0–0.2 m/s occurring only at the center of the pool. In contrast, models 2 and 3 exhibited minimum velocities near the fishway wall. The flow velocity through the submerged orifice in pool 4 ranged from 1.25–0.89 m/s for model 1, 0.99–0.77 m/s for model 2, and 0.70–0.40 m/s for model 3. In pool 10, the corresponding velocities were 1.17–0.94 m/s for model 1, 1.08–0.89 m/s for model 2, and 0.70–0.44 m/s for model 3. These results indicate that the baffles effectively guided the flow within the fishway pool and reduced the flow velocity through the submerged orifice. Consequently, model 3, incorporating two baffles, demonstrated better performance than the original pool pass design (model 1).

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	ADV, eco-hydraulic, fishway, hidraulik, pool passes
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC173 Orifices. Nozzles. Jets T Technology > TC Hydraulic engineering. Ocean engineering > TC424 Water levels
Divisions:	Faculty of Civil, Environmental, and Geo Engineering > Civil Engineering > 22101-(S2) Master Theses
Depositing User:	Nurhayati Dyan Eka
Date Deposited:	22 Jul 2026 03:53
Last Modified:	22 Jul 2026 03:53
URI:	http://repository.its.ac.id/id/eprint/67321

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