Pravitasari, Inneke Yulistanty (2019) Analisis Kekuatan Spread Mooring Akibat Squall. Other thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Squall adalah peristiwa terjadinya kenaikan kecepatan angin yang meningkat tajam secara tiba-tiba yang dapat mencapai kecepatan hingga 50 m/s dan diikuti dengan perubahan arah angin yang kemudian terjadi peluruhan kecepatan pada angin tersebut. Salah satu tempat sering terjadinya squall adalah di Laut Natuna Utara dimana terdapat FSO Belida yang ditambat dengan sistem tambat spread mooring. Beban lingkungan squall tersebut berdampak pada respon FSO dan tali tambat. Tugas akhir ini akan menganalisa dampak squall dengan mensimulasikan squall dalam domain waktu dengan variasi durasi squall yaitu 2.5 menit, 5 menit, dan 10 menit. Dan pada simulasi squall 10 menit akan divariasikan periode gelombang untuk mengetahui pengaruhnya terhadap respon struktur. Hasil analisis simulasi squall 10 menit menunjukkan bahwa terjadi kenaikan pada tegangan tali tambat sebesar 34% untuk kondisi operasi dan sebesar 70% untuk kondisi ekstrem. Untuk kenaikan terbesar offset pada sumbu X terjadi sebesar 352% untuk kondisi operasi dan 367% untuk kondisi ekstrem. Sedangkan untuk sumbu Y terjadi kenaikan offset berturut-turut sebesar 65% untuk kondisi operasi dan 115% untuk kondisi ekstrem. Sedangkan variasi nilai periode pada lingkungan squall durasi 10 menit tidak memberikan dampak cukup signifikan pada perubahan tension dan offset. Pengaruh durasi squall mempengaruhi tension tali tambat dan offset vessel dimana semakin pendek durasi squall akan menghasilkan tension mooring line dan offset vessel besar.
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Squalls are mesoscale sudden wind-speed increases which rapidly reach a peak wind speed (up to 50 m/s) which followed by changes of wind direction and then decay to low speeds in a span of 60 to 90 minutes. One of the places where squall often occurs is in the North Natuna Sea where Belida FSO is moored with a spread mooring system. The environmental load of squall has an impact to the FSO response and mooring lines. This final project will analyze the impact of squall by simulating squall in the time domain with variation of squall duration i.e. 2.5 minutes, 5 minutes, and 10 minutes. For the squall 10 minutes simulation will vary the wave period to determine its effect on structural response. The results of the simulation analysis of squall 10 minutes show that there is an increase in mooring tension of 34% for operating conditions and 70% for extreme conditions. For the largest increase in offset on the X axis, it occurs at 352% for operating conditions and 367% for extreme conditions. While for the Y axis there is an increase in offset by 65% for operating conditions and 115% for extreme conditions. While the variation of period values in the squall with a duration of 10 minutes does not have a significant effect on changes in tension and offset. The effect of the duration of squall affects tension and offset vessel where the shorter of squall duration will produce a large tension of mooring line and offset vessel.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | FSO, Squall, Spread Mooring, Tension Mooring, Offset |
| Subjects: | T Technology > TC Hydraulic engineering. Ocean engineering T Technology > TC Hydraulic engineering. Ocean engineering > TC1680 Offshore structures |
| Divisions: | Faculty of Marine Technology (MARTECH) > Ocean Engineering > 38201-(S1) Undergraduate Thesis |
| Depositing User: | Inneke Yulistanty Pravitasari |
| Date Deposited: | 01 Jul 2024 04:21 |
| Last Modified: | 01 Jul 2024 04:21 |
| URI: | http://repository.its.ac.id/id/eprint/69191 |
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