No abstract

No abstract

The present study uses Quikscat data to assess the offshore wind energy potential at the Eastern part of Indonesia, around the Sulawesi and Maluku Islands. Weibull distribution with two parameters is used to represent the characteristics and distribution of the wind model. In order to confirm the accuracy of computations, statistical and numerical methods are used to compute the Weibull parameters which are regression analysis, maximum likelihood method and moment method. The obtained power density is used to draw monthly wind power maps for the sea areas around the islands. The maps are used to determine the most suitable location of a mobile conversion system every month. Moreover, by assuming that a NM72/2000 NEG Micon is installed, Monte Carlo Simulation is performed to determine the expected power percentage produced by the system every month.

No abstract

Keselamatan merupakan priorotas utama dalam hukum pelayaran, maka perlu dirancang sedimikian rupa termasuk kebutuhan listrik untuk keadaan darurat/emergency di kapal. Dalam hal kelistrikan, sangat dibutuhkan sistem-sistem yang mendukung pengoprasian menyangkut peralatan apa saja yang harus beroperasi pada kondisi darurat/emergency di kapal. Perencanaan dan pemilihan kapasitas generator harus mampu memenuhi kebutuhan dan harus memperhatikan keefektifan daya generator yang dipilih karena akan berhubungan dengan masalah investasi atau harga yang dikeluarkan. Oleh karena itu, penelitian ini melakukan perhitungan ulang kapasitas generator dan juga melakukan perencanaan/penggambaran ulang diagram kelistrikan (wiring diagram) berdasarkan keadaan di lapangan dan dibandingkan dengan daya output dari generator untuk kondisi darurat/emergency. Dari penelitian ini, dapat dibuktikan secara teoritis bahwa perencanaan sistem kelistrikan di kapal dapat diterapkan secara nyata dan sesuai dengan ketentuan berlaku sehingga pada saat pemasangan instalasi listrik di kapal dan di masa yang akan datang dapat diandalkan demi kepuasan bagi pemilik kapal.

To evaluate the exploitation potential of wind energy in the coastal area of South Sulawesi, Indonesia, an investigation on the economic feasibility of this project was performed. A 300-watt horizontal wind turbine was used as an example installed turbine. The wind speed range of 4-7 m/s which was the wind speed data in the coastal area of South Sulawesi was computed. The main economic analysis method employed was Capital Budgeting Analysis (CBA) method. In this method, 4 (four) indicators were used to evaluate the feasibility of the project which are payback period (PBP), net present value (NPV), internal rate of return (IRR), and benefit-cost ratio (BCR). A visual basic computer program based on the CBA method was also developed to make the computation more convenient. From the study, it was found that the wind speed range of 4-6 m/s resulted in a non-feasibility project while the highest wind speed (7 m/s) was found to be quite strong to make the project feasible.

No abstract

Due to the increasing of fuel prices and volatile of environmental regulations, it is a challenge for Naval Architects to design a ship dealing with an optimum ship’s total resistance. The conventional design of catamaran hull has not satisfied yet to reduce the ship’s total resistance. This paper presents a numerical investigation into gaining sufficient reduction of the ship’s total resistance of catamaran through optimizing her hull form. To achieve this research objectives, a numerical optimization modelling coupled with a Computational Fluid Dynamics (CFD) approach has been successfully conducted. Several parameters such as length, beam and draft of catamaran hull have been taken into account towards reducing the ship’s total resistance. Here, the simulation constraints are applied to obtain the optimum dimension, where the length, beam and draft of the catamaran hull were optimized within the range of 1.2 m to 1.5 m, 0.11 m to 0.14 m and 0.07 m to 0.08 m, respectively. In general, the optimization simulation revealed that the optimum dimension of the catamaran hull resulted in reduction of the total ship’s resistance. The results showed that the optimum length, beam and draft of hull led to reduce by 21.08%, 16.95% and 17.91%, respectively. Merely, this numerical optimization simulation provides a useful way for reducing the total ship’s resistance of the catamaran at the preliminary design stage.