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Analisa Hidrodinamika Kapal Container Sarat Rendah Ali, Baharuddin; Firdaus, Nurman; Nurhadi, N
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 14, No 3 (2017): Oktober
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (895.825 KB) | DOI: 10.14710/kpl.v14i3.15594

Abstract

Kapal container sebagai sarana angkutan barang berpengaruh vital terhadap laju percepatan perekonomian nasional. Kondisi perairan Indonesia yang kedalaman dan fasilitas pendukung pelabuhan bervariasi serta efisiensi operasional kapal menjadi pertimbangan dalam mendesain kapal. Penggunaan kapal sarat rendah tipe barge bermesin sebagai pengangkut container, Self Propelled Container Barge (SPCB) saat ini banyak menjadi pilihan operator kapal dalam melayani pengiriman barang dengan container. Penelitian ini menyajikan analisis hidrodinamika kapal SPCB 100 TEUs dengan metode pengujian model meliputi seakeeping, turning dan zig-zag manuvering serta resistance test. Dari hasil uji seakeeping diketahui bahwa respon gerak kapal pada kondisi gelombang sea-state 4 masih dalam batas toleransi dengan memperhatikan kombinasi kecepatan dan arah heading kapal. Kinerja  manuvering turning dan zig-zag kapal dalam batas aman yang ditetapkan IMO. Dari hasil uji resistance didapatkan kecepatan maksimal yang optimum kapal adalah 12 knot. Selain besaran terukur, uji hidrodinamika dengan model memberikan gambaran fenomena saat kapal beroperasi di laut, sehingga menjadi informasi yang penting dalam desain dan operasional kapal.
The Wave Heights Distribution of Random Wave Based on Ocean Basin Firdaus, Nurman; Ali, Baharuddin; Nasir, Mochammad; Muryadin, M
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 17, No 3 (2020): October
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v17i3.31021

Abstract

The wave height parameter in ocean waves is one of the important information for a marine structure design. The present paper investigates the results of wave heights distribution from laboratory-generated for single sea state. Data of the random wave time series collected at the ocean basin are analyzed using the wave spectrum and compared with the theoretical spectrum in this study. The random wave data is varied with four sea states consisting of sea states 3, 4, 5 and 6 obtained from laboratory measurements. The parameter conditions of generated sea waves are represented by a value of significant wave height and wave peak period in the range of sea states. The individual wave heights data in each sea state are presented in the form of exceedance probability distribution and the predictions using a linear model. This study aims to estimate the wave heights distribution using the Rayleigh and Weibull distribution model. Furthermore, the accuracy of the wave heights distribution data's prediction results in each sea state has been compared and examined for both models. The applied linear models indicate similar and reasonable estimations on the observed data trends.
Recent Advancements in Ocean Current Turbine Blade Design: A Review of Geometrical Shape, Performance and Potential Development using CAE Fajri, Aprianur; Jurkovič, Martin; Kandimba, Enock Michael; Lutanto, Agus; Falah, Fajrul; Adiputra, Ristiyanto; Firdaus, Nurman
Mekanika: Majalah Ilmiah Mekanika Vol 23, No 2 (2024): MEKANIKA : Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v23i2.87374

Abstract

The global energy demand is experiencing a significant surge, reaching 442 exajoules in 2023. The urgency to develop renewable energy sources intensifies as global energy needs continue to escalate, coupled with the detrimental impact of fossil fuel consumption on climate change. Ocean current energy has emerged as a promising renewable energy source due to its predictability and minimal environmental impact. However, the efficiency and reliability of Ocean Current Turbines (OCTs) depend highly on their blades' design and performance. This review provides a comprehensive overview of recent advancements in ocean current and tidal current turbine blade design and the challenges and issues associated with their operation and maintenance. The paper discusses various design aspects, including blade geometry, material selection, hydrodynamic performance optimization, and bio-inspired designs. Additionally, it highlights the common failures and degradation mechanisms of turbine blades, such as fatigue, erosion, and cavitation. Furthermore, the review explores the challenges faced in developing and deploying OCTs, such as improved blade durability, cost-effectiveness, and environmental compatibility.
Hydrodynamic Analysis of Patrol Vessel Based On Seakeeping and Resistance Performance Firdaus, Nurman; Ali, Baharuddin
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 60 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 (711.611 KB) | DOI: 10.36842/jomase.v60i1.66

Abstract

The patrol vessel must have a good performance criteria for a sea worthiness.The hydrodynamic aspects analysis of a ship design is a main step conduct by designer. This study describes an analysis of motions and ship resistance. The seakeeping test conducted two variations of a ship loading condition. The ship's motion response to sea-state 4 waves with the heading of 180 and 135 deg. The ship resistance test with two draft conditions is calculated by model test and numerical simulation. The ship motion response is expressed in terms of the probability distribution. The values of ship resistance are presented as a non-dimensional graph with a Froude number. The ship loading conditions on a vertical center of gravity is higher resulting in a larger ship motion response than lower vertical center of gravity, as well as the heading of wave is very influential. The results of resistance test above Froude number 0.3, a resistance of ship increase and began to appear hump resistance around a hull.
Experimental Study of the Probability Distributions on the Seakeeping Performance of Monohull and Catamaran Design Ali, Baharuddin; Firdaus, Nurman
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 47 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 (1297.325 KB) | DOI: 10.36842/jomase.v47i1.174

Abstract

A safety and a comfort criteria of ship, one of them which can be known from ability of the ship motion on sea wave. The development of maritime technology in particular shipbuilding, catamaran ship design is one of the considerations in modern ship design, in addition to monohull ship design. This research describes the analysis of seakeeping model test of monohull and catamaran ship. The seakeeping model test is performed on sea- state 4 with a heading of 45 deg, 90 deg, 135 deg and 180 deg. Ship motion responses in the form of heave, pitch and roll motion, are presented in the form of the probability distribution curves. From the results of seakeeping test, it can be seen that the catamaran ship provides motion response relatively smaller than the monohull ship.