Aries Sulisetyono

THE MINI-SUBMARINE DESIGN FOR MONITORING OF THE POLLUTANT AND SEWAGE DISCHARGE IN COASTAL AREA

Pollutant and sewage discharge in coastal area is most unmonitored. Its make a slow preventive action by government to protect an ecosystem of coastal area from the environmental damage. The development of mini-submarine vehicle is selected to do the monitoring of pollution and sewage discharge in the coastal area continuously. The robotic technology might be adopted to make the vehicle is most suitable to do the monitoring mission. So that, the vehicle is equipped with the wireless instrument and it can be controlled by an operator on sea surface. The camera is also installed on the vehicle in order to capture the underwater environment and send it to the operator. In this paper, the procedure of a designing mini-submarine for the monitoring of underwater pollutant and sewage discharge in the coastal area is described. Due to the particular mission, the vehicle has to have a good stability and hydrodynamic performances, and also it able to load the entire equipment requirements.

Wave Load Analysis of the Corvette Ship in the Sea Water of Indonesia

Wave load prediction of ship should be considered in the design stage of ship’s construction. The excessive of wave load might cause a structural failure of ship during operational in seaway. The bending moment might be experienced on the ship structure that it contributes to stress concentration on the particular part of construction. This paper describes the prediction of bending moment and shear forces of the warship corvette type considered to the sea condition of Indonesia. The 3D diffraction theory was adopted to analyze ship’s motion responses, bending moments, and shear forces numerically. In this numerical simulation, the variations of speed and heading angle of ship were performed with respect to environmental condition of sea state 4, 5, 6 and 7. The simulation results had shown that the maximum shear force and bending moment was occurred on the area of mid-ship.

Heading Analysis of Weathervaning Turret Moored Units

This paper presents the heading analysis study of weathervaning turret moored unit. Design wave heading is to be in accordance with the operational conditions for the sea states contributing the most to the long term value of the dominant load effect. From the heading analysis over each of the sea states contained in the time-series, the mean heading of the floating structure can be obtained.The objective of this study is to assess heading analysis outcome as function of heading probability occurrences of weathervaning turret moored floating units and to identify dominance environment load component act to the system.In order to achieve the above objective, the numerical model has been developed. The model is generate a vessel model by describing the capability to weathervane. It will be performed with MOSES software packages and numerical tools, both in the time-domain and frequency-domain.The heading analysis results indicates that the most affected external forces is dedicated by wind, it is seen the relative heading between wind and vessel heading is quite small (<10degree) with large occurrence probability (up to 60%). The proposed double static approach method to solve heading analysis has been investigated by comparing to former approach which is found a good result agreement between them.

Fatigue Life Prediction for Warship Operation in Indonesian Water

The fatigue life of a corvette ship structural detail was predicted by using a spectral fatique analysis. The fluctuated wave load act to the ship’s structure in regular wave was estimated by using Diffraction Theory. The stress spectrum was defined using analytical approach consider to the design constructions of ship. The operational routes of a corvette ship were determined in Indonesian water condition for a year period of ship’s mission. The sea condition was ilustrated in term of wave spectrum which was developed using the ITTC formula. The spectral response of stress bending moment was calculated by multiplication of wave spectrum and stress bending moment in regular wave for certain life time. Furthermore, the estimation of the fatigue life was performed by using Palmgren-Miner rule during its life time of operation. Finally, the fatigue life of a corvette ship was predicted about 84 years based on the mission and water condition of Indonesia.

Marine Current Technology Design to Support the Poteran Island Economy Based on Fisheries

Poteran is a small island as part of Sumenep Madura Indonesia where it has the natural resorces to be developed into a sustainable small island. Increasing the local economy based on fisheries sector has a high potential to be developed. In small fisheries industry, the electrical energy is necessary needed, so that the marine power plant technology is relevant to be employed in this island. This paper describe the concept design of current power technology which is suitable to be implemented in the island consider to the enviromental sea condition. Potential current energy captured is identified based on the measurement of current speed for the short period of time at the coastal area of island. Futhermore, the turbine design of current power technology is introduced as well as the design of floating platform.

The Evaluation of a Rigid Sail of Ship Using Wind Tunnel Test

This paper described the evaluation of rigid sail performances by using the wind tunnel test. The rigid sail models were developed in the three variations of shape geometry which was having the same value of aspect ratio. The tests were performed to investigate the performances of sail models in terms of lift, drag, resultant, driving and heeling coefficient. The three sail models were tested at the variation of angle of attack such as 15o, 20o and 25o respectively, and it was fluided by a uniform flow of air with three different speeds. The comparisons of test results were evaluated to look for which sail models had the best performance. Based on the test results, Model 2 which is a triangle shape had generated a maximal efficiency and thrust force compare to the other models.Keywords: rigid sail, wind tunnel, sailing ship, renewable energy

Studi Gerakan Sloshing terhadap Tangki Kotak (Rectangular Tank) Dengan dan Tanpa Pelat Memanjang (Baffle) Akibat Gerakan Rolling Kapal Dengan Metode Computational Fluid Dynamics (CFD)

Abstrak—Sloshing dapat diartikan sebagai gerakan bebas dari fluida cair di dalam sebuah wadah . Masalah sloshing menjadi fenomena penting dalam tangki muatan cair, karena dapat menyebabkan kerusakan pada struktur dalam tangki . paper ini menjelaskan pengaruh besarnya pressure pada tangki kotak dengan dan tanpa penambahan pelat memanjang (baffle) ketika terjadi sloshing yang diakibatkan gerakan rolling yang terjadi pada kapal. Pemodelan tangki dilakukan 2D berbentuk tanki kotak (rectangular tank) dengan ukuran panjang 46.92 m dan tinggi 32.23 m menggunakan software gambit,. variasi model tangki ada 2 yaitu tanpa dan dengan penambahan 1 buah baffle dengan ukuran tebal 1 m dan tinggi 6 m dengan ketinggian cairan 15%, 45%, dan 75%. Proses simulasi dilakukan dengan meode Computational Fluid Dynamic (CFD) menggunakan software Fluent. Dari hasil simulasi dapat disimpulkan bahwa baffle berhasil berfungsi sebagai peredam pressure ketika volume muatan lebih rendah dari tinggi baffle yaitu dalam hal ini volume 15%, namun ketika pada volume muatan 45% dan 75% baffle tidak dapat berfungsi sebagai peredam pressure karena adanya baffle dapat menimbul gaya permukaan cairan ketika cairan lng menghantam baffle yang menyebabkan tinggi cairan lng menjadi lebih tinggi sehingga ketika terjadi gerakan tangki maka dapat menambah besar pressure untuk menghantam dinding-dinding tangki.