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Abstrak :
ABSTRAK
The water-wave interaction with submerged breakwaters is examined to determine the reflection and transmission coefficients. Three types of breakwaters are considered, namely, a submerged breakwater extending from the sea bed until below the waterline, a breakwater extending from above the seawater to some distance below, and a breakwater extending all the way from the seabed with slit at some distance from the bed. In all three cases the breakwaters are assumed to be rigid, thin, and impermeable, and subjected to linear monochromatic waves, and the fluid motion is idealized as linearized, two-dimensional potential flow. A computationally efficient method - an eigenfunction technique with a mixed boundary condition - is used to determine the velocity potential anywhere in the region of flow. The least-square method has been utilized in the solution for the mixed boundary condition. The accuracy of the solution is demonstrated by comparing the numerical values for the transmission coefficient with those obtained from experiments or other analytical solutions but with water depth restrictions. Numerical results in terms of both reflection and transmission coefficients are presented for each case.

Abstrak :
Kecepatan kapal adalah suatu nilai yang penting guna untuk memenuhi standart kecepatan dinas kapal. Pengoptimalan sistem propulsi kapal adalah faktor yang perlu diperhatikan. Beberapa penelitian untuk meningkatkan sistem propulsi kapal sudah banyak dilakukan, salah satunya adalah wake equalizing ducts dan kort nozzle. Penelitian tersebut bertujuan untuk mengarahkan aliran air lebih banyak dari sisi bawah dan sisi samping lambung kapal menuju ke baling - baling kapal. Cara ini dimaksudkan agar dapat meningkatkan efisiensi baling - baling, yang nantinya akan meningkatkan kecepatan kapal secara langsung. Dengan tujuan yang sama dengan wake equalizing ducts dan kort nozzle, maka water tunnel dirancang dengan rancangan yang lebih sederhana. Water tunnel adalah suatu terowongan air berbentuk kotak lengkung yang terhubung dari bawah lambung kapal ke buritan menuju baling - baling. Water tunnel ini memanfaatkan aliran air bawah lambung kapal untuk mengubah energi mekanik menjadi energi kinetik setelah aliran air masuk ke baling - baling. Cara ini diharapkan dapat mengalirkan air lebih terarah menuju ke baling - baling, sehingga efisiensi baling - baling meningkat, yang dapat terukur langsung melalui kenaikan kecepatan kapal. Penelitian ini dilakukan dengan cara ekperimental dan simulasi untuk mengetahui fenomena yang terjadi akibat penggunaan water tunnel. Cara Eksperimental dilakukan untuk membandingkan kecepatan kapal yang terjadi antara penggunaan water tunnel dan tidak menggunakan water tunnel, dan cara simulai dilakukan guna mengetahui fenomena aliran yang terjadi di dalam water tunnel. Sehingga pada akhir penelitian didapatkan analisa kecepatan yang terjadi akibat penggunaan water tunnel pada kapal pelat datar. Dari hasil uji kecepatan secara eksperimen didapatkan kenaikan 19-32% dengan menggunakan water tunnel pada kapal pelat datar, dan dari hasil simulasi didapatkan kontur kecepatan aliran di dalam water tunnel dengan batasan pengujian yang dihasilkan. ......Ship velocity is the important value to meet the standard of ship velocity service. Optimalization ship propulsion system is a factor that have to consider. Some studies to improving ship propulsion system has been done, one of study is wake equalizing ducts and kort nozzle. In this study aims to direct the flow more water fro the bottom and side of hull towards the propeller. This method is conducted to improve the efficiency propeller, that will increase the velocity of the ship directly. With the same purpose as wake equalizing ducts and kort nozzle, the water tunnel is designed with a simply design. Water tunnel is a duct of water that shaped is curve box and connected from bottom hull ship toward aft propeller. Water tunnel takes the water flow from under the hull to convert mechanical energy to be kinetic energy after the water flow enter propeller. This method is expected to drain the water more directed toward the propeller, so the efficiency would increase, which can be measured directly through the ship velocity increase. The research was done by experimental and simulation to know the phenomenon that occurs due to using water tunnel. Experiment test conducted to compare the velocity ship that happen between unsing water tunnel and not using water tunnel, and with simulation test conducted to know the flow phenomena in water tunnel. So at the end of study was obtained that analisys of the velocity result using water tunnel system on the flat plate ship. Result of the ship velocity test experiment, obtained 19-32% increase by using a water tunnel on a flat plate ship, and from simulation test result obtained the value of contours flow in the water tunnel with boundary of study result.

Abstrak :
Perkembangan USV atau kapal tanpa awak di dunia sudah berkembang pesat. Desain lambung yang sering digunakan pun beraneka ragam, namun masih belum banyak yang menggunakan teknologi SWATH. Dalam penelitian ini dihasilkan sebuah inovasi desain pada bidang USV berbasis SWATH yang memiliki karakter hambatan yang rendah, bentuk kamuflase, memiliki daya muat yang besar, stabilitas yang baik, dan banyak fungsi yang tidak dimiliki oleh USV lainnya. Inovasi desain ini diberi nama Sea Ghost yang dapat dikembangkan agar dapat lebih canggih lagi di masa depan. Dari penelitian ini dihasilkan suatu grafik performa desain yang menggambarkan performa lambung USV dari berbagai tipe dan ukuran. ......Development of USV or unmanned vessel in the world is growing rapidly. The usual hull designs are also varied, but most of them aren’t use SWATH technology. In this study, an innovative design in USV based on SWATH technology is obtained with characterization low resistance, camouflage form, large capacity, good stability, and more functions that are not owned by any other USV. This innovation named Sea Ghost which can be developed to become more sophisticated in future. A design performance graph is obtained from this study that depicts the USV hull performance of various types and sizes.

Abstrak :
This encyclopedia adopts a wider definition for the concept of ocean engineering. Specifically, it includes (1) offshore engineering: fixed and floating offshore oil and gas platforms; pipelines and risers; cables and moorings; buoy technology; foundation engineering; ocean mining; marine and offshore renewable energy; aquaculture engineering; and subsea engineering; (2) naval architecture: ship and special marine vehicle design; intact and damaged stability; technology for energy efficiency and green shipping; ship production technology; decommissioning and recycling; (3) polar and Arctic Engineering: ice mechanics; ice-structure interaction; polar operations; polar design; environmental protection; (4) underwater technologies: AUV/ROV design; AUV/ROV hydrodynamics; maneuvering and control; and underwater-specific communicating and sensing systems for AUV/ROVs. It summarizes the A–Z of the background and application knowledge of ocean engineering for use by ocean scientists and ocean engineers as well as nonspecialists such as engineers and scientists from all disciplines, economists, students, and politicians. Ocean engineering theories, ocean devices and equipment, ocean design and operation technologies are described by international experts, many from industry and each entry offers an introduction and references for further study, making current technology and operating practices available for future generations to learn from. The book also furthers our understanding of the current state of the art, leading to new and more efficient technologies with breakthroughs from new theory and materials. As the land resources approach the exploitation limit, ocean resources are becoming the next choice for the sustainable development. As such, ocean engineering is vital in the 21st century.

Abstrak :
This book contains a selection of research papers presented at the 11th and 12th International Ship Stability Workshops (Wageningen, 2010 and Washington DC, 2011) and the 11th International Conference on Stability of Ships and Ocean Vehicles (Athens, 2012). The book is directed toward the ship stability community and presents innovative ideas concerning the understanding of the physical nature of stability failures and methodologies for assessing ship stability. Particular interest of the readership is expected in relation with appearance of new and unconventional types of ships; assessment of stability of these ships cannot rely on the existing experience and has to be based on the first principles. As the complexity of the physical processes responsible for stability failure have increasingly made time-domain numerical simulation the main tool for stability assessment, particular emphasis is made on the development an application of such tools. The included papers have been selected by the editorial committee and have gone through an additional review process, with at least two reviewers allocated for each. Many of the papers have been significantly updated or expanded from their original version, in order to best reflect the state of knowledge concerning stability at the time of the books publication. The book consist of four parts: Mathematical Model of Ship Motions in Waves, Dynamics of Large Motions, Experimental Research and Requirements, Regulations and Operations.