International Journal of Metacentre

Application of Tensile Testing on Ulin Wood And Bungur Wood as Main Materials for 20 GT Traditional Fishing Vessel Hull

Andi Mursid Nugraha Arifuddin — 2023-06-28

Fishing boats in North Penajam Paser are made by combining 2 types of wood in the hull. This combination of wood types is carried out to save the material procurement budget. Bungur wood is the alternative choice for shipyards for hull material combined with Ulin wood. For this reason, this paper shows the differences in the tensile strength performance of these 2 types of traditional wooden ship hull materials. The experimental method of destructive testing of the type of Tensile test was applied in this study. Where the experimental results show that the tensile strength of the crepe is 22% lower than the tensile strength of ulin wood. Meanwhile, in terms of stiffness, crepe wood is superior to ulin wood, where the difference reaches 22.22%. Bungur wood still has the potential to be used for wooden ships with an LoA (length over all) value of <15 meters or for ships that have a lower hydrostatic load than that which can be accepted by Bungur wood.

Study of the Impact of Biofouling on Ship Resistance Using Autodesk CFD

Rosmani Rosmani — 2023-06-28

Biofouling, the accumulation of marine organisms on ship hulls, poses a substantial challenge in the maritime industry. Over time, organisms like algae and molluscs adhere to hull surfaces, creating a biofouling layer that disrupts water flow and increases ship resistance. This study investigates the effects of biofouling on ship resistance and fluid flow patterns along the hull. Data collection involved measuring key ship dimensions, analyzing ship lines plan drawings, and measuring biofouling thickness. Autodesk Computational Fluid Dynamics (CFD) software was used to calculate ship resistance and analyze fluid flow along the hull. Two conditions were compared: a hull without biofouling and a biofouled hull. At a speed of 1.220 m/s, the biofouled ship model exhibited a resistance of 3,739 N, while the clean hull had a resistance of 3,280 N, indicating a 13.642% resistance increase due to biofouling. Fluid flow analysis revealed complex flow patterns along the biofouled hull, potentially reducing operational efficiency. These findings underscore the importance of biofouling prevention and control measures in minimizing resistance and maintaining operational efficiency. A deeper understanding of fluid flow characteristics related to biofouling allows ship operators and companies to make informed decisions about vessel maintenance, reducing environmental impacts and operational costs. This research contributes to addressing biofouling challenges in the maritime industry.

Experimental Study on Bow Slamming of a Ship

Andi Dian Eka Anggriani — 2023-06-28

This study discusses about the critical issue of slamming phenomena in ship design, emphasizing its impact on ship safety, environmental concerns, and fuel consumption. The drop tests has been used to investigate bow slamming pressures and internal strain at various drop angle. The results indicated peak pressures at different sensors, with higher drop angles resulting in increased impact pressures and internal strains due to augmented velocity, angular momentum, surface area contact, hydrodynamic effects, and gravitational forces.