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INDONESIA
KAPAL Jurnal Ilmu Pengetahuan dan Teknologi Kelautan
Published by Universitas Diponegoro
ISSN : 18298370     EISSN : 23019069     DOI : 10.14710/kapal.
Core Subject : Science,
Earth & Planetary Sciences
Jurnal ini merupakan Jurnal Ilmiah untuk mengembangkan ilmu dibidang Ilmu Pengetahuan & Teknologi Kelautan. Jurnal ini diterbitkan oleh Teknik Perkapalan Universitas Diponegoro 3 (tiga) kali dalam 1 tahun pada bulan Februari, Juni dan Oktober.
Arjuna Subject : -
Articles 408 Documents
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Potential Wind Energy Analysis in Maluku Region with Savonius Turbine using CFD Approach Louhenapessy, Jandri; Simanjuntak, Antoni; Luhulima, Richard Benny
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 2 (2024): June
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i2.62391

Abstract

The Maluku region, also known as the Moluccas, is an archipelago in Indonesia with exceptional wind patterns ideal for wind power generation. Its strategic location between the Pacific and Indian Oceans creates strong and consistent winds due to temperature differences, making it an optimal site for wind energy production. Harnessing wind power in Maluku can significantly benefit Indonesia and the global renewable energy sector by providing a reliable and sustainable energy source to reduce greenhouse gas emissions and combat climate change. Furthermore, the development of wind power in Maluku could create new economic opportunities and incentives for the local community, promoting sustainable development and reducing the reliance on fossil fuels. A study was conducted to assess the viability of wind energy in Maluku, utilizing a Sonius turbine and computational fluid dynamics (CFD) methodology. By varying the center distance between the Savonius blade radius and its rotational axis, researchers aimed to optimize the turbine's design for maximum energy extraction. The simulations showed that turbine model design significantly impacts performance, with Model 2 outperforming Model 1 due to smoother airflow and more efficient rotation. The pressure distribution on the semicircular blades also influenced turbine performance, with Model 1 producing higher force but slower rotation speed compared to Model 2. The simulations showed that Turbine Model 1 produced a higher average force and power output compared to Turbine Model 2. According to the simulations, Model 1 showcased a higher average power output of 66.5 Watts, while Turbine Model 2 only achieved 46.6 Watts. However, Turbine Model 1 had a slower rotation speed due to its larger radius. Under consistent wind conditions, Turbine Model 1 was capable of producing 5.5% more energy than Turbine Model 2. Choosing an efficient turbine model is crucial for maximising the energy production from wind resources. The findings from this study contribute to a comprehensive understanding of the turbine's behavior and can aid in optimizing its design for maximum energy extraction.
Analysis of Ambulance Ship Design in Karimunjawa Waters reviewed by Stability and Seakeeping Putra, Gusma Hamdana; Soelistijono, Rachmad Tri; Setyawan, Prasastya Dhohir
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 1 (2024): February
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i1.60839

Abstract

The inadequate health facilities in the Karimunjawa Islands region still need attention. In particular, patients who have to be referred to the hospital still have problems in terms of transportation. This research presents the results of simulations of ambulance ship designs adapted to Karimunjawa conditions. A ship with a length of 8 m, width of 2.2 m, height of 1.1 m, and draft height of 0.37 m is analyzed regarding stability and seakeeping referring to IMO HSC Code 2000 Annex 8. Several parameters are determined, such as load, speed, significant wave height, and direction. The results in terms of stability show that loads of 100%, 50%, and 25% are still acceptable. Then, the results from seakeeping show that at a speed of 23 knots and significant wave height, especially in the diagonal wave direction of the ship, it is not acceptable
Analysis of the Application of the Rest Hour Maritime Labor Convention 2006 on MV. Pan Energen Crews to Improve Working Conditions With Analytical Hierarchy Process (AHP) Method Aprillia, Namira; Mulyatno, Imam Pujo; Mursid, Ocid; Yulianti, Serliana
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 20, No 3 (2023): October
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v20i3.58807

Abstract

The contribution made by the crew is very important for the welfare of the company and the performance on board. But their well-being has not been paid enough attention in the maritime world. Heavy workloads and working hours and lack of implementation of rest hours trigger human error and are prone to fatigue. The implementation of the Maritime Labor Convention 2006 has contributed significantly to the improvement of the working conditions of the crew.  The purpose of this study is to determine the right criteria and strategic solutions in helping to improve the application of rest hours to crew members. Criteria and strategy solutions were obtained through the Analytical Hierarchy Process (AHP) and Expert Choice methods are used as supporting software for calculations. The stages of observation, interviews, dissemination of questionnaires, modeling and choice are processes carried out in data processing.  Rest time criterias with a weight value of 0.534 and an inconsistency value of 0.004466 was the main criteria chosen by the respondents. Meanwhile, Sleep Duration is a strategy solution chosen as the top priority with the weight value of 0.220 with an inconsistency value of 0. The results of the two inconsistencies each have a CR value of < 0.1 indicating that the results of rest hour application data processing based on the 2006 Maritime Labor Convention can be declared consistent and accurate.
Implementation of Indonesian Flag for Electricity Standards on Non-Conventional Vessel at Palipi Harbor Tona, Tasdik; Nurwahidah, Nurwahidah
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 2 (2024): June
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i2.64500

Abstract

This research aims to analyze the current level of application of electricity standards on Indonesian-flagged non-convention ships by Gross Tonnage (GT 7-35), identify the obstacles faced in implementing electricity standards on Indonesian-flag non-convention ships by Gross Tonnage (GT 7-35) and how to make efforts in increasing the application of electrical standards on Indonesian-flagged non-convention ships by Gross Tonnage (GT 7-35). The research method used is a qualitative method with data collection techniques involving observation, documentation, and interviews with related parties. The data analysis technique used is qualitative descriptive analysis. The results show that the electrical condition of non-convention ships varies greatly depending on factors such as ship type, ship size, and the level of maintenance performed. The constraints faced in the implementation of electrical standards on Indonesian-flagged non-convention ships by Gross Tonnage (GT 7-35) are limited resources, understanding and awareness, changes in technology and regulations, and lack of routine maintenance and inspections; and collaboration between authorities, ship owners, and ship crews has not been maximized in the implementation of electrical standards, as well as the absence of training programs or resources offered by related parties to improve understanding and skills related to ship electricity.
Development of Maintenance Scheduling Model for the Safety Operational of Ship Machinery Handani, Dhimas Widhi; Uchida, Makoto
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 2 (2024): June
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i2.61582

Abstract

Risk management of ship machinery is an important issue since machinery out of order can run into danger, especially for ships at sea. This paper implements risk based maintenance (RBM) to minimize the frequency and consequences of ship machinery failure. Not only the common steps of RBM, such as identification of problem, risk assessment, risk evaluation, and maintenance planning are conducted, but this paper also proposes a new model called ship position estimation. The preliminary identification i.e. identification of failure causes and symptoms as well as the history of failure time will be looked at first. In the risk assessment, quantification of the consequences of failure (Cof) considers system performance loss, while the probability of failure (Pof) is obtained from the reliability analysis of the failure time history. Risk evaluation compares the result of the risk assessment with the risk acceptance criteria in order to determine the level of risk. The proposed model of ship position estimation recognizes the ship position on the voyage when the analyzed machinery is in a high level of risk. Maintenance planning is further carried out to keep the machinery under the risk acceptance level. This paper utilizes a method called system dynamics to create simulation for each step of the RBM. As a case study, the parts of the pumps in the main engine cooling system are analyzed. The result of this paper is a proposed maintenance interval which is reasonable enough compared with the standard for pump maintenance. Additionally, the ship position is included when the pump reaches a high level of risk.
Experimental Investigation of Oxy-Hydrogen Injection in Natural Gas/Diesel Dual-Fuel Engine: Performance and Emission Analysis under Low Load Operation Ariani, Betty; Felayati, Frengki Mohamad; Batutah, Mohammad Arif
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 1 (2024): February
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i1.61692

Abstract

The pursuit of achieving zero carbon emissions by 2050 has led to the implementation of green technologies in the maritime industry. One crucial aspect is the adoption of alternative fuels, with a focus on non-fossil fuels to enhance energy efficiency and minimize emissions during ship operations. This study explores the innovative dual fuel diesel – Compressed Natural Gas (CNG) technology, which offers relatively low emissions with uncomplicated modifications to the diesel engine. CNG is injected into the intake manifold, addressing the need for cleaner fuel options. However, the evolution of this technology has encountered challenges such as methane slip resulting from incomplete combustion. This research proposes an intervention using hydrogen within the combustion chamber to improve combustion quality. Oxy-hydrogen gas (HHO), a carbon-free fuel derived from water through electrolysis, is considered as a potential solution. The utilization of HHO serves as a substitute for pure H2 due to its more feasible production and application, considering the global limitations in hydrogen storage and usage in transportation. The study aims to investigate the impact of HHO on the performance and emissions of dual fuel engines. Experimental tests are conducted under low loads to simulate critical operational points of the engine. Results indicate that the dual fuel system exhibits significant fuel savings, particularly with increasing injection duration. However, the need for additional oxygen to enhance combustion perfection must be balanced. HHO injection demonstrates the potential to improve engine performance, leveraging the oxygen content in HHO and the positive characteristics of hydrogen with its high Lower Heating Value (LHV). Furthermore, the research suggests that HHO injection can mitigate methane slip issues associated with dual fuel engine operations, offering a promising avenue for emission reduction
Evaluating Wave Potential and Assessing the Economic Viability of Wave Energy Converters in the South Java Seas Waskito, Kurniawan Teguh; Yudho, Renaldi H; Yanuar, Yanuar; Rahardjo, Gema P
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 20, No 3 (2023): October
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v20i3.60005

Abstract

As an archipelagic nation, Indonesia holds substantial potential for wave energy as a renewable resource. Certain coastlines of islands facing the Indian Ocean, particularly in the western and southern regions, exhibit significant wave energy throughout the year. To identify suitable locations for Wave Energy Converter (WEC) installation, it is essential to assess wave hindcast data. This study utilizes NOAA and ERA5 reanalysis wave data to analyze wave characteristics in Indonesia from 2008 to 2018. Data processing with Ocean Data View is employed to estimate key wave parameters at various locations, including significant wave height, mean wave period, and mean wave direction. Two locations in the South Java seas were identified for WEC installation based on this research. The average values for the period 2008 to 2018 indicate a significant wave height of around 2m, with a maximum height of 5m, a wave period of 10–14s, and a wave direction of 195–210 degrees. Notably, NOAA data suggests a higher estimation of significant wave height compared to ERA5 data. The average annual wave power potential based on ERA5 and NOAA is 164.43 MW/m and 252.15 MW/m, respectively. Furthermore, this study incorporates an economic simulation for the construction of a multi-point absorber WEC. The objective is to offer insights into the Levelized Cost of Electricity (LCOE) and compare it with other WEC technologies. Assuming a WEC capacity of 130 kW, the total construction cost is estimated at $2,093,725, resulting in a Levelized Cost of Energy (LCOE) of $91/MWh.
The Effect of Tip Clearance Kaplan Ducted Propeller in Offshore Supply Vessel (OSV) on Hydrodynamics Winarno, Arif; Sakti, Gedhe Angkoso Nur Sofa; Sugianto, Erik
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 3 (2024): October
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i3.64772

Abstract

A ducted propeller is a modification of a propeller by adding a duct or nozzle. The purpose of using a ducted propeller is to increase thrust, increase propeller efficiency, and encourage better ship movement. This is suitable for Offshore Supply Vessel (OSV) vessels operating on offshore platforms to support oil drilling activities. In designing a kort nozzle, one of the most important components is the tip clearance, the distance between the edge of the propeller and the inner nozzle. The diameter of the kort nozzle can affect the thrust efficiency of the propeller. Due to the blade momentum theory for ducted propellers, the volume of water passing through the propeller should be as large as possible, with the smallest possible flow velocity. In this study, numerical simulations using the Computational Fluid Dynamics (CFD) method were carried out to determine the effect of tip clearance on thrust and torque on a ducted propeller with a MARIN foil 19A nozzle type and tip clearance of 10 mm, 20 mm, and 30 mm. From all models, the highest thrust and torque values were obtained from the nozzle 19A tip clearance 10 mm model with thrust 367,413 kN and torque 315,338 kNm. The relationship between tip clearance and thrust is inversely proportional; the greater the tip clearance, the smaller the value of thrust, and the same is true with torque.
Modification of Double Helical Kapiler Pipe to Reduce Temperature in a 100 Liter Capacity Freezer on the Ship Prayogi, Urip; Felayati, Frengki Mohamad; Sugianto, Erik; Syaifuddin, Muhammad Rizal
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 2 (2024): June
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i2.63798

Abstract

The freezer machine is one of the tools on board and serves to maintain the temperature of food ingredients to keep it in good condition and fresh. Given the importance of this, the cooling machine is a tool that functions to make durable foodstuffs by naturally maintaining the temperature. Standard freezer machines produce temperatures only up to -15oC. Modification of the freezer machine needs to be done so that the temperature reaches a lower minus again by changing the capillary pipe from standard to double helical. The purpose of this study is to analyze the effect of double helical capillary pipes on the working performance of a 100-liter capacity freezer cooling machine using R600A refrigerant. In this study the frezzer machine was modified by replacing a single capillary pipe into a double helical. The method used is to conduct experiments to take data to determine the temperature produced and calculate the Coefficient of Performance (COP)  before and after modification. The results of this study are the lowest temperature in the double helical capillary pipe variation during the three-hour test obtained a temperature in the range of -20.2oC while the standard capillary pipe obtained a temperature in the range of -14.9oC. The average COP for standard capillary pipes is greater at 2.773 compared to the COP of double helical capillary pipes which is 2.421. At double helical temperature values are cooler than standard capillary pipes. However, the disadvantage is that the COP of the double-helical capillary pipe is lower than the COP of the standard capillary pipe.
Systematic Considerations for a Ballast Water Treatment System (BWTS) Retrofits: A Review Sari, Wanda Rulita; Gunawan, Gunawan
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 21, No 1 (2024): February
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v21i1.61944

Abstract

As a country that has more than half of the country's total territorial waters, Indonesia is highly dependent on shipping activities. Therefore, knowledge of policy updates for each ship from IMO must also be taken into account, one of which is the policy regarding the Ballast Water Management System, which requires every ship to be installed with a Ballast Water Treatment System in order to achieve the goal of a green environment in voyage areas by inhibiting the spread of microorganisms that endanger the area that is caused by ballast water. This regulatory update then creates problems, especially for ships that have been operating for a long time, because the ship has to comply with the standards for D-1 and then also have to comply with the D-2 standards according to the time specified in the convention. So, this review article will discuss the solution to the issues with retrofitting ballast water treatment systems as the addition of a new system to the existing system on a ship that has sailed and pay attention to conceptual aspects consisting of considerations and operations to find the type of ballast water treatment that suits each ship's needs by analyzing the advantages and disadvantages of each technology type method. There is also consideration for several stages that are commonly used to determine the type of treatment, starting with assessment and planning requirements, selection of space, compliance with BWMS regulations, selection of the ballast water treatment system method, engineering drawing, installation planning, and commissioning. Apart from that, several related innovation considerations were also discussed, including the development of alternative treatment technology, which has the potential for efficiency both in operational aspects and safety standards. Based on research developments, retrofitting the Ballast Water Treatment System with the ultra-violet (UV) treatment is well known as the common treatment beside the electrolysis treatment. The results obtained show that the ultra-violet (UV) method is one of the most efficient treatments when viewed from the way it works and the time duration for the treatment process. This proves that ultra-violet treatment can produce maximum efficiency if the selection of needs and consideration of maximized aspects also exceed the safety aspect as well.

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