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Journal : Archipelago Engineering

ANALISA NUMERIK PEMILIHAN GEOMETRI FIN BURITAN UNTUK KAPAL-KAPAL SPEED BOAT YANG BEROPERASI DI AMBON DAN SEKITARNYA Eliza R de Fretes
ALE Proceeding Vol 1 (2018): Archipelago Engineering (ALE)
Publisher : Fakultas Teknik Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ale.1.2018.80-85

Abstract

Abstrak Kapal speed boat merupakan kategori kapal cepat yang mempunyai kecepatan dinas yang tinggi, ini ditandai dengan Froude Number (Fn) yang lebih besar dari 1.2. Dalam pengoperasiannya speed boat mempunyai permasalahan yang sangat kruisal tentang trim, dimana pada kondisi kapal kosong sering kali mengalami trim buritan sehingga nahkoda tidak dapat melihat ke depan, adanya hambatan yang besar, serta arah kemudi yang sulit dikemudikan. Selain itu pada saat mulai berjalan speed boat mempunyai kecenderungan menukik ke haluan, hal inipun perlu untuk mendapat perhatian khusus. Kajian yang disampaikan dalam penelitian ini mengkaji variasi sejumah bentuk dan konfigurasi bentuk peralatan peredam trim yang digunakan pada speed boat, lebih khususnya dengan meninjau pada pola aliran yang terbentuk dan lift yang ditimbulkan. Pengkajian dilakukan dengan menerapkan pemodelan numerik, selanjutnya hasil numerik divalidasi dengan pengujian laboratorium untuk mendapatkan hasil yang menyerupai kondisi sebenarnya. Setelah itu kapal dirancang dan dibuat dalam bentuk prototype. Hasil yang diperoleh untuk aerofoil foil buritan dengan type NACA 010 mendapat gaya lift sesuai dengan kemiringan nya yaitu 5 derajat, panjang foil 10% panjang garis air, serta koefisien kecepatan kapal antara 2 sampai dengan 7 knot, koefisien lift yang diperoleh adalah 0,003; koefisien drag adalah 0,007, serta koefisien momen yang dihasilkan adalah 0,01; Pada kemiringan 10 derajat mempunyai koefifien lift 0,009 dan koefisien drag 0,015, akan tetapi koefisien momen mendfapat nilai nol, sedangkan yang diperlukan adalah besarnya momen untuk mengangkat kapal
THE RESISTANCE ASPECT OF FISHING BOAT SKIPJACK POLE AND LINE Wolter R Hetharia; Eliza R de Fretes; Reico H Siahainenia
ALE Proceeding Vol 4 (2021): Archipelago Engineering (ALE)
Publisher : Fakultas Teknik Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ale.4.2021.1-7

Abstract

The operation of fishing vessels skipjack pole and line contributes in catching tuna and skipjack fishes particularly in Indonesian waters. A previous study conducted by the authors found that there was no suitable method provided for the resistance computation atearly ship design phase. Besides, there was aninitial trim existed on the vessel during the operation which contributes for the resistance. The purpose of the study is to find the difference of resistance between the model test and the existing methods. The study was executed also to find the effect of initial trim of the vessel. The study began with collecting the database of a parent ship then to develop and transform into a model-scale for testing purpose in the towing tank. The results of model test were converted to the full-scale vessel. The resistance of full-scale vessel was computed based on the Holtrop and Guldhammer methods. The result of full-of resistance obtained from the model test and the methods were collected, evaluated and compared. The results showed the difference of the resistance for all methods. The result of model test is greater 21 % than that of Holtrop method at the service speed of 10 knots. Meanwhile, the result of model test is lower 14 % than that of Gulhammer method at the same speed. In addition, at the speed of 10 knots the initial trim of 0.5O increase 5 % ofthe resistance, the initial trim of 1O increase 10 % of resistance and the initial trim of 2O increase 16 % of resistance compared to the vesselwithout initial trim. In conclusion, the existing resistance methods are not suitable to be applied for skipjack pole and line fishing vessels. In addition, the initial trim contributes to increase the resistance and should be avoided during the vessel operation.
PENGARUH KEMIRINGAN POROS BALING-BALING TERHADAP KECEPATAN PERAHU KETINTING M Nur Habib; Eliza R de Fretes; Sonja T. A. Lekatompessy
ALE Proceeding Vol 4 (2021): Archipelago Engineering (ALE)
Publisher : Fakultas Teknik Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ale.4.2021.18-22

Abstract

Ketinting boat in operation using propeller with engine located on deck. This position resulted in the propeller dipping by making a certain angle, in addition the depth of the propeller also overlapped the speed of the ship.This phenomenon is something very important to be examined with the aim of obtaining maximum speed in relation to the angle of tilt of the propeller and the amount of maximum thrust required.The method used is an experimental method in which the model of the ship and propeller are made according to the desired scale, and so conduct testing on the towing tank.The test result obtained is a slope that creates the optimal speed of the ketinting boat is at a slope of 18° with a speed of V = 5.05 knots and a maximum thrust of PT = 13.15 kW.