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"Catamaran resistance is very complex compared to monohull resistance, so it is particularly worthy of research. The below-water-level hull form influences the fluid flow characteristics around the ship, which either increases or decreases the total resistance. This study focuses on developing a new hull form by using the Lackenby Method to modify an existing hull form in such a way that reduces the total resistance. The total resistance was calculated using computational fluid dynamics, since the Navier-Stokes equation is built into the Tdyn software.

The research results show that hull form changes can in fact decrease or increase the ship?s total resistance. The best new hull form was chosen for its value of least total resistance."

"Pentamaran atau kapal lima lambung merupakan inovasi lambung terbaru dalam penelitian kapal multihull yang bertujuan untuk mengurangi konsumsi bahan bakar. Penelitian sebelumnya menyatakan bahwa kecepatan tinggi dan konfigurasi tertentu, kapal pentamaran memiliki hambatan yang sangat rendah. Pada penelitian ini dilakukan analisis hambatan kapal kepada lima kapal pentamaran dengan S/L 0.19 yang memiliki variasi peletakkan lambung. Metode yang digunakan adalah metode eksperimen dan metode CFD menggunakan Ansys Fluent 17.2 software package. Pada penelitian ini dihasilkan bahwa konfigurasi yang memiliki koefisien hambatan terkecil di seluruh Froude Number adalah konfigurasi Inboard Outer. Hal ini dikarenakan adanya interaksi gelombang yang menguntungkan antara lambung-lambung pada kapal pentamaran Inboard Outer.

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Pentamaran or five hulls design is new innovation in multihull research to decrease fuel consumption. The previous research declared that the pentamaran hull has very low resistance at high speed for certain configuration of hull which is determined by configuration and form of each hull. This research is aim to find the effect of asymmetric hull placement on pentamaran ship S L 0.19. CFD Computational Fluid Dynamics method and experimental method are used for validation process. The result of this research is the Inboard Outer asymmetric hull configuration has the lowest resistance coefficient due to the benefits of interaction of waves between each hull of pentamaran."

"High speed catamaran and multihull high speed marine vessel have become very popular in the last two decades. The catamaran has become the vessel of choice for the majority of high speed ferry operators worldwide. There have been significant advances in structural materials, and structural design has been combined with higher power density and fuel efficient engines to deliver ferries of increasing size. The multihull has proven itself to be a suitable configuration for active power projection across oceans as well as for coastal patrol and protection, operating at high speedd for insertion or retrieval with a low energy capability. At present there is no easily accessible material covering the combination of hydrodynamics, aerodynamics, and design issues including structures, powering and propulsion for these vehicles. Coverage in High Speed Catamarans and Multihulls includes an introduction to the history, evolution, and development of catamarans, followed by a theoretical calculation of wave resistance in shallow and deep water, as well as the drag components of the multihull. A discussion of vessel concept design describing design characteristics, empirical regression for determination of principal dimensions in preliminary design, general arrangement, and methods is also included. The book concludes with a discussion of experimental future vehicles currently in development including the small waterplane twin hull vessels, wave piercing catamarans, planing catamarans, tunnel planing catamarans and other multihull vessels."

"Float merupakan komponen pada pesawat amfibi yang berfungsi sebagai bagian yang memberikan gaya apung pada pesawat ketika berada di permukaan air. Agar pesawat amfibi dapat lepas landas dengan jarak yang minimum, float harus didesain seoptimal mungkin untuk mendapatkan hasil hambatan total yang kecil. Oleh karena itu, biomimikri terhadap ikan layar digunakan dalam merancang float dengan harapan hambatan yang dihasilkan oleh float dapat berkurang mengikuti karakteristik ikan layar. Jarak melintang antar float yang terdapat pada nilai clearance (S/L) juga merupakan factor yang sangat berpengaruh terhadap hambatan total yang dihasilkan. Penelitian ini bertujuan untuk mendapatkan nilai clearance yang optimal untuk diterapkan pada jarak antar float hasil adaptasi ikan layar agar mendapatkan hambatan total air yang minimum. Pengujian dilakukan secara numerik dengan simulasi CFD (Computational Fluid Dynamics) menggunakan perangkat lunak ANSYS Fluent dengan Froude Number dari 0,40 hingga 0,70 dengan interval 0,05 dan variasi clearance sebesar 0.20, 0.25, 0.30, 0.35, 0.40 dan 0,45. Hasil penelitian memperlihatkan pengaruh besar clearance dalam mereduksi hambatan total float. Koefisien hambatan terkecil terjadi pada clearance 0,45 sedangkan koefisien hambatan terbesar terjadi pada clearance 0,2

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Float is a component of a seaplane that functions as a part that provides buoyancy to the aircraft when it is on the water surface. In order for the seaplane to take off with a minimum distance, the float must be designed as optimal as possible to obtain a small total drag. Therefore, biomimicry of sailfish used in designing floats in the hope that the resistance generated by the float can be reduced following the characteristics of sailfish. The transverse distance between floats contained in the clearance value (S / L) is also a factor that significantly influences the resulting total resistance. This study aims to obtain the optimal clearance value to be applied to the distance between floats adapted by sailfish in order to obtain a minimum total water resistance. The test was carried out numerically with a CFD (Computational Fluid Dynamics) simulation using ANSYS Fluent software with a Froude Number from 0.40 to 0.70 with an interval of 0.05 and a clearance variation of 0.20, 0.25, 0.30, 0.35, 0.40 and 0.45. The results showed the large effect of clearance in reducing total float resistance. The smallest resistance coefficient occurs at a clearance of 0.45, while the largest coefficient of resistance occurs at a clearance of 0.2"

"The relative significance of the parallel middle body and stern form in the wake formation of single-screw large ships and their contribution to the ship’s viscous resistance are studied by using computational fluid dynamics (CFD). A 10450-DWT tanker is considered by varying the ratio of the parallel-middle-body’s length to the ship’s length (Lmb/L) and by varying the shape of the stern form from a V-like to a U-like underwater stern transom section. In all the calculations, the principal dimension and the displacement of the ships are kept constant. A larger value for the parallel-middle-body relative length (Lmb/L) of ships with the same stern form results in a larger drag coefficient but does not affect the nominal wake fraction significantly. A change in the shape of the underwater stern form, from a V-like to a U-like section, results in a much larger drag coefficient ascribed to the much larger wake fraction. The stern form dominantly affects the nominal wake fraction and the ship’s viscous resistance compared to the parallel-middle-body relative length."

""Drag Reduction of Complex Mixtures discusses the concept of drag reduction phenomena in complex mixtures in internal and external flows that are shown experimentally by dividing flow patterns into three categories. The book is intended to support further experiments or analysis in drag reduction. As accurately modeling flow behavior with drag reduction is always complex, and since drag reducing additives or solid particles are mixed in fluids, this book covers these complex phenomena in a concise, but comprehensive manner.Comprehensively addresses a range of drag reduction themes involving different kinds of complex mixtures. Provides data to support further experimentation and computer modeling of drag in complex flow. Includes an introduction to the nature and characteristics of different kinds of complex mixtures"

"Indonesia sebagai negara kepulauan yang memiliki banyak wilayah laut membutuhkan keamanan untuk menjaga kedaulatannya. Salah satu kapal yang melindungi wilayah laut Indonesia adalah Kapal Patroli. Stern Foil adalah inovasi yang dapat digunakan pada kapal patroli. Inovasi ini menggunakan prinsip yang sama seperti Ductile dan Interceptor tetapi dengan menggunakan Hydrofoil. Ductile dan Interceptor digunakan untuk membuat Wetted Surface Area (WSA) pada transom berkurang dengan membuat vortex di bawah transom, perubahan semacam ini akan meningkatkan kecepatan dan mengurangi hambatan total kapal. Dan Hydrofoil adalah alat seperti sayap di pesawat yang akan digunakan pada kapal. Penelitian ini bertujuan untuk menganalisa efek Stern Foil yang dipasang ke kapal patroli dengan parameter-parameter hidrodinamik meenggunakan 3˚ dan 0˚ Stern Foil, Froude Number 0,6-1,3, dan tiga pembebanan yang berbeda (beban penuh, setengah, dan kosong). Penelitian ini menyimpulkan bahwa kerja optimal untuk stern foil berada di beban setengah penuh, dengan reduksi hambatan sekitar 23.268% dan 26.705% masing-masing dengan Stern Foil 3 dan 0 di Froude Number 1.1 dan Froude Number 0.9. Penelitian ini dilakukan dengan menggunakan program Computational Fluid Dynamics yaitu Ansys.

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Indonesia as an archipelagic country with lot of sea territory needs safety for Indonesias marine areas. One of the vessels that protects Indonesias marine territory is Patrol Vessel which is looking after territory itself. Stern Foil is an innovation that could be used on patrol vessels. This innovation uses the same principle as Ductile and Interceptor but with Hydrofoil. Ductile and Interceptor used to make wet area on transom of the hull decrease by creating vortex below transom, this kind of change will produce advantageous for hull itself such as increasing speed and reducing drag resistance. And Hydrofoil is a tools like the wings on aircraft that will be used on ships. This study aims to elaborate the Stern Foil assembled to the patrol vessels with parameters of hydrodynamic parameters in 3 Stern Foil and 0, Froude Number 0.6 - 1.3, and three different displacement (full, half, and empty displacement). The result concluded that the optimum work for stern foil was in half displacement, with reduction approximately 23,268% and 26.705% with 3 and 0 Stern Foil respectively at Froude Number 1.1 and Froude Number 0.9. This research was conducted using Computational Fluid Dynamics program like Ansys"

"Haluan kapal merupakan bagian pertama yang akan menghadang air yang mengalir saat kapal bergerak maju. Pada kapal selam, bentuk haluan sangat berpengaruh baik terhadap peletakan peralatan akustik, maupun besarnya tahanan yang akan dihasilkan. Penelitian ini berfokus untuk meninjau pengaruh bentuk haluan pada kapal selam tanpa appandages terhadap karakteristik tahanannya. Haluan akan divariasikan berdasarkan persamaan Hull Envelope yang mengatur desain bentuk haluan pada kapal selam. Simulasi komputasi dengan CFD dipilih sebagai metode untuk memprediksi hasil tersebut. Hasil menunjukkan bahwa nf= 2 merupakan bentuk haluan paling optimum dengan nilai tahanan total terendah yang memiliki luasan haluan yang cukup besar.

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The bow of the ship is the first part that will hit the running water when the ship moves forward. In the submarine, the bow shape is very influential both on the laying of acoustic equipment, and for the magnitude of resistance to be generated. This study focuses on reviewing the influence of the bow shape on submarines without appandages to the characteristics of its resistance. The bow will be varied based on the Hull Envelope equation that governs the bow shape design on the submarine. The computational simulation with CFD is chosen as a method to predict the result. The results show that nf 2 is the most optimum bow shape with the lowest total resistance value that has a large enough extent."