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Review on Development of Ice-Ship Afrizal, Efi; Koto, J.
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 34 No 1 (2016): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36842/jomase.v34i1.405

Abstract

In the early stage, sailing by ships at North and Artic Seas should be able to break ice which is commonly called as ice-breakers. Dimensions of the ice breakers were not big enough to be used as a cargo or large carrier. As the demand to merchant ships has been increased, the development technologies on hull form design and propulsion system for ice-going ship have been improved gradually. This paper discussed historical ice ships, the development of ships in ice such as ice breaker, double acting ship and offshore floating by taken two parameters into account which is hull form design and propulsion system.
Analyze Performance of Double Acting Tanker While Running Astern in Ice Condition Afrizal, Efi; Koto, Jaswar
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 44 No 1 (2017): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1365.91 KB) | DOI: 10.36842/jomase.v44i1.182

Abstract

The increasing of shipping activities through the Northern Sea Route (NSR) and growth of oil and gas activities in Arctic and Sub-Artic regions require suitable design of ice-going ships and planning operations in ice. In 2002, Sumitomo Heavy Industries has built advanced ice-ship called "Double Acting Tanker". This paper discussed application of new method to determine ice resistance of Double Acting Tanker running ahead in ice condition. The simulation was carried out at 1 m ice thickness in unfrozen and frozen channels and 0.5 m ice thickness in level ice condition. The simulation results were compared with experimental results.
Empirical Approach to Predict Ship Resistance in Level Ice Koto, Jaswar; Afrizal, Efi
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 45 No 1 (2017): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1526.766 KB) | DOI: 10.36842/jomase.v45i1.179

Abstract

Prediction of resistance of ship level ice is very important in initial stage of ship design due to related to propulsion and engine power of a ship. As model scale test is very expensive therefore an accurate tool is required to predict the resistance of a ship in ice. A semi empirical method to predict ship resistance in level ice based Koto method was presented. The ship resistance consisted of ice breaking force due to flexural strength of ice, submersion force due to buoyancy, friction force contact between ice and hull and loss momentum force due to collision. The simulation results were verified with experimental data of three icebreakers: MT Uikku, Hellay and Araon. The method was also compared with other empirical methods: Lindqvist, Riska, Keinonen and Jeong. It was founded that the average errors using the proposed method was 3 % for MT Uikku, 0.3 % for Hellay and 0.4 % for Araon.
Buckling and Deflection of Ice Sheet Caused by Ship Koto, J; Afrizal, Efi; M.A, Wahid
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 62 No 1 (2018): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (922.096 KB) | DOI: 10.36842/jomase.v62i1.104

Abstract

The movement of ice ship gradually gives load to the ice sheet, along with that, the ice sheet will react in proportion to the load of the ship. The phenomenon of interaction between ice and hull of ship has been studied by researchers through empirical mathematical simulation and experiment. This paper discusses the phenomena of ice sheet buckling and deflection caused by a ship sailing in ice level. The ice sheet buckling and deflection is analyzed based on using Finite Element Method based on Euler and Cantilever methods. The methods were described from general deflection equation for a beam. Simulation was carried out using Abaqus running ahead and astern at several speeds of 0.4m/s, 0.5m/s and 0.6m/s.
Performance Evaluation of Fixed Pitch Propellers: Flow Visualization of Cavitation in Unmanned Surface Vehicles Asral, Asral; Nurhidayat, Muhammad; Herisiswanto, Herisiswanto; Afrizal, Efi; Hafis, Muhammad Hazel; Samad, Rahimuddin; Muhammadu, Muhammadu Masin
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 69 No 2 (2025): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36842/jomase.v69i2.538

Abstract

This study was conducted to determine a suitable and appropriate propeller for use on unmanned surface vehicles. The tests involved varying the number of blades-2, 3, and 4 of fixed pitch propellers type to assess thrust, propeller performance during straight-line motion and maneuvering, as well as the flow patterns around the propeller that have the potential to cause cavitation. The experiments were carried out in both a reservoir and a test tank. The results showed that the average thrust produced by the 2-blade, 3-blade, and 4-blade propellers was 13.32 N, 17.13 N, and 12.78 N, respectively. In the straight-line test over a 20-meter distance, the average speeds achieved were 1.49 m/s (2 blades), 1.40 m/s (3 blades), and 1.21 m/s (4 blades). For maneuvering, the average speeds recorded were 0.80 m/s, 0.61 m/s, and 0.49 m/s, respectively. Flow pattern analysis around the propellers revealed that cavitation occurred in almost all conditions and blade number variations. The fewer the blades, the more clearly cavitation bubble formation was observed. Similarly, increasing the propeller rotational speed can lead to a higher rate of bubble formation. Overall, the 3-blade propeller yielded the best performance for unmanned surface vehicle, offering an optimal balance of thrust, speed, maneuverability, and more controlled cavitation potential.
Development of Rotary Fatigue Test Equipment Based on the Joseph Marin Approach Prasetyo, Anang; Afrizal, Efi; Nazaruddin, Nazaruddin
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 67 No 3 (2023): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36842/jomase.v67i3.344

Abstract

This paper proposed the development of rotary fatigue test equipment. This equipment was used to test the JIS S45C steel, validated using the Joseph Marin approach. Analyzing the fatigue strength of JIS S45C steel using the Joseph Marin approach was compared to experimental testing. The dimension of the test specimens was based on the ASTM E 466. The test data was displayed in the form of an S-N curve. The test results showed the fatigue strength of JIS S45C steel on the whole that was close to each other, experimentally and using the Joseph Marin approach. In the infinite life region, it is known that the fatigue strength based on the Joseph Marin approach was lower than experimental tests. Therefore, if JIS S45C steel had received a hefty load repeatedly, it would fail more quickly.
Effect of Slip-to-Roll Ratio on Wear Rate and Friction Coefficient of Palm Oil-Base Biolubricant with Additive of Graphene Cupu, Dedi Rosa Putra; Adji, Aryo Kuncoro; Anuar, Kaspul; Afrizal, Efi; Nazaruddin
Proksima Vol 2 No 1 (2024): Jurnal ProKsima
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/proksima.v2i1.23

Abstract

During machine is in operation, some machine elements will contact causing a rubbing between the elements. When the contacting parts is subjected to a mechanical force, a phenomenon called friction and wear arise. Contacting of both elements with the same tangential velocity refers to pure rolling contact which means there is no slip between them. Lubricants are usually used between the contacting materials to reduce friction and wear. Nowadays, commercial lubricants are from mineral oils which are dangerous to human beings and the environment. An alternative to reduce the use of mineral oil is by using vegetable-based oils. This research was experimentally conducted to study the effect of slip-to-roll ratio (SRR) on the wear rate and coefficient of friction for biolubricant made of palm oil and graphene nanolayers as additives using disc-on-disc tribometer. The experimental results show that the value of the wear rate and friction coefficient is directly proportional to the value of the slip ratio on the two discs. This means that the greater the slip ratio that occurs, the greater the value of the wear rate and friction coefficient produced.