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[ES] En este proyecto se pretende realizar el diseño de todas las partes que forman un vehículo hovercraft. En este caso la electrónica se basará en un microprocesador Arduino, el diseño físico del vehículo se realizará mediante el programa openScad. Para el control del hovercraft se utilizará un terminal móvil basado en Android por lo que se desarrollará una aplicación para este fin mediante la plataforma app inventor.

[ES] En este proyecto se pretende realizar el diseño de todas las partes que forman un vehículo hovercraft. En este caso la electrónica se basará en un microprocesador Arduino, el diseño físico del vehículo se realizará mediante el programa openScad. Para el control del hovercraft se utilizará un terminal móvil basado en Android por lo que se desarrollará una aplicación para este fin mediante la plataforma app inventor.

[ES] En este proyecto se pretende realizar el diseño de todas las partes que forman un vehículo hovercraft. En este caso la electrónica se basará en un microprocesador Arduino, el diseño físico del vehículo se realizará mediante el programa openScad. Para el control del hovercraft se utilizará un terminal móvil basado en Android por lo que se desarrollará una aplicación para este fin mediante la plataforma app inventor.

Indonesia merupakan negara kepulauan dengan wilayah perairan kurang lebih 70%.  Memperhatikan kondisi geografis tersebut serta meningkatnya lalu lintas antar pulau, menuntut penggunaan sarana transportasi yang cepat, ekonomis, aman dan nyaman.  Hovercraft merupakan alternatif jawaban yang tepat untuk digunakan di Indonesia.  Salah satu kelebihan yang dimiliki sarana transportasi ini adalah tidak membutuhkan dermaga atau pelabuhan khusus karena bersifat amfibi dan memiliki kecepatan yang relatif cukup tinggi.  Teknologi yang dibutuhkan tidak rumit dan tidak mahal serta hampir seluruh kebutuhan materialnya terdapat di Indonesia. Oleh karena itu Hovercraft sangat cocok untuk dikembangkan di Indonesia, baik untuk kebutuhan perhubungan dunia sipil maupun militer. Pemakaian Hovercraft di Indonesia, terutama Indonesia Bagian Timur dan Tengah akan membuka jalur transportasi baru yang akan mendorong perkembangan perekonomian daerah tersebut melalui kepariwisataan dan kelancaran angkutan hasil jasa daerah, baik dari laut maupun produk-produk kerajinan dan juga industri untuk dipasarkan ke luar daerah maupun ke luar negeri. Di Indonesia sampai saat ini telah dihasilkan desain Hovercraft 20 penumpang, laboratorium prototype 2 penumpang dan reengineering 12 penumpang.

El proyecto consistirá en una revisión bibliográfica sobre la historia, funcionamiento, aplicaciones y usos de los hovercraft, así como de los elementos que lo componen, con el objetivo de adquirir los conocimientos necesarios para diseñar y construir una maqueta radio control propia. El hovercraft tendrá una eslora de 0,63 m de longitud y se realizaran pruebas con diferentes materiales para escoger el más adecuado para su funcionamiento. Se buscarán materiales lo más ligeros posibles ya que al tratarse de un hovercraft se deberá sustentar en el aire. Dicha sustentación será posible gracias a un colchón de aire hinchado a partir de un motor eléctrico y una hélice. Debido a este cojín de aire, el aerodeslizador se levantará del suelo y se reducirá la fuerza necesaria para moverlo. En cuanto a la propulsión, del vehículo, también se usará una hélice y un motor eléctrico. Y para el diseño, se utilizará algún modelo ya existente como guía, a partir del cual, se realizarán los planos, la modelización y el diseño 3D, a través del programa AUTOCAD y del software 3DS MAX. Por último para el control remoto, se usará una placa Arduino y un módulo WI-FI, con el objetivo de poderse utilizar un ordenador o una aplicación para móvil como emisor.

Indonesia merupakan negara kepulauan dengan wilayah perairan kurang lebih 70%.  Memperhatikan kondisi geografis tersebut serta meningkatnya lalu lintas antar pulau, menuntut penggunaan sarana transportasi yang cepat, ekonomis, aman dan nyaman.  Hovercraft merupakan alternatif jawaban yang tepat untuk digunakan di Indonesia.  Salah satu kelebihan yang dimiliki sarana transportasi ini adalah tidak membutuhkan dermaga atau pelabuhan khusus karena bersifat amfibi dan memiliki kecepatan yang relatif cukup tinggi.  Teknologi yang dibutuhkan tidak rumit dan tidak mahal serta hampir seluruh kebutuhan materialnya terdapat di Indonesia. Oleh karena itu Hovercraft sangat cocok untuk dikembangkan di Indonesia, baik untuk kebutuhan perhubungan dunia sipil maupun militer. Pemakaian Hovercraft di Indonesia, terutama Indonesia Bagian Timur dan Tengah akan membuka jalur transportasi baru yang akan mendorong perkembangan perekonomian daerah tersebut melalui kepariwisataan dan kelancaran angkutan hasil jasa daerah, baik dari laut maupun produk-produk kerajinan dan juga industri untuk dipasarkan ke luar daerah maupun ke luar negeri. Di Indonesia sampai saat ini telah dihasilkan desain Hovercraft 20 penumpang, laboratorium prototype 2 penumpang dan reengineering 12 penumpang.

The steady increase in volume of goods to be transported over land and water has necessitated the development of efficient and alternative methods of transportation. In current practices considerable amount of transportation delay is caused due to switching between different modes of transportation resulting in economic losses. Another difficulty in the transportation sector arises when handling extremely large objects, such as wind turbines and cargo containers. In order to overcome these difficulties, an alternative method of transportation has been proposed recently. The proposed alternative method consists of the development of a formation control framework using hovercrafts. Formation control is a widely researched topic due its potential benefits in reducing the system cost, structure flexibility and improving the efficiency of the overall system. State-of-the-art methods for formation control are focused towards developing a controller to track a predefined trajectory, and the trajectory generation is an additional problem which is addressed off-line. A path tracking formation control framework is an area which has received less attention in the literature and can have possible improvements. Hence, this thesis work answers the research question of generating a feasible path for a set of initial and final conditions, and tracking the generated path. Model Predictive Controller (MPC) is a promising framework, because of its constraint handling capabilities. Hence, it accounts for the major component of this thesis. A new framework for formation control is proposed which uses spatial-domain parametrization instead of the conventional time-domain parametrization. MPC being a computationally expensive task, the proposed framework reduces the number of decision variables and constraint evaluations which can help to achieve the desired Real Time performance. The specific research question addressed in this thesis work is to develop a path tracking formation control, Systems and Control, Delft Center for Systems and Control, Mechanical, Maritime and Materials Engineering

The steady increase in volume of goods to be transported over land and water has necessitated the development of efficient and alternative methods of transportation. In current practices considerable amount of transportation delay is caused due to switching between different modes of transportation resulting in economic losses. Another difficulty in the transportation sector arises when handling extremely large objects, such as wind turbines and cargo containers. In order to overcome these difficulties, an alternative method of transportation has been proposed recently. The proposed alternative method consists of the development of a formation control framework using hovercrafts. Formation control is a widely researched topic due its potential benefits in reducing the system cost, structure flexibility and improving the efficiency of the overall system. State-of-the-art methods for formation control are focused towards developing a controller to track a predefined trajectory, and the trajectory generation is an additional problem which is addressed off-line. A path tracking formation control framework is an area which has received less attention in the literature and can have possible improvements. Hence, this thesis work answers the research question of generating a feasible path for a set of initial and final conditions, and tracking the generated path. Model Predictive Controller (MPC) is a promising framework, because of its constraint handling capabilities. Hence, it accounts for the major component of this thesis. A new framework for formation control is proposed which uses spatial-domain parametrization instead of the conventional time-domain parametrization. MPC being a computationally expensive task, the proposed framework reduces the number of decision variables and constraint evaluations which can help to achieve the desired Real Time performance. The specific research question addressed in this thesis work is to develop a path tracking formation control, Systems and Control, Delft Center for Systems and Control, Mechanical, Maritime and Materials Engineering

A Computational Fluid Dynamics (CFD) tool is developed in this thesis to solve complex fluid-structure interaction (FSI) problems. The fluid domain is based on Smoothed Particle Hydro-dynamics (SPH) and the structural domain employs large-deformation Finite Element Method (FEM). Validation tests of SPH and FEM are first performed individually. A loosely-coupled SPH-FEM model is then proposed for solving FSI problems. Validation results of two benchmark FSI problems are illustrated (Antoci et al., 2007; Souto-Iglesias et al., 2008). The first test case is flow in a sloshing tank interacting with an elastic body and the second one is dam-break flow through an elastic gate. The results obtained with the SPH-FEM model show good agreement with published results and suggest that the SPH-FEM model is a viable and effective numerical tool for FSI problems. This research is then applied to simulate a two-dimensional free-stream flow interacting with a deformable, pressurized surface, such as an ACV/SES bow seal. The dynamics of deformable surfaces such as the skirt/seal systems of the ACV/SES utilize the large-deformation FEM model. The fluid part including the air inside the chamber and water are simulated by SPH. A validation case is performed to investigate the application of SPH-FEM model in ACV/SES via comparison with experimental data (Zalek and Doctors, 2010). The thesis provides the theory of the SPH and FEM models incorporated and the derivation of the loosely-coupled SPH-FEM model. The validation results have suggested that this SPH-FEM model can be readily applied to skirt/seal dynamics of ACV/SES interacting with free-surface flow.

We investigate the use of particle filter (PF) estimation techniques on a hovercraft vehicle in an office environment. Monte Carlo Localization (MCL) with particle filtering is a popular method for localizing robots with laser range finders. In maps featuring long, uniform corridors though, a PF can produce low confidence estimates. When used as feedback to control an unstable vehicle this can prove fatal. This is because, unlike grounded wheeled vehicles, an airborne hovercraft requires accurate localization not only for path planning, but for stabilization as well. We solve the low confidence problem using a secondary networked robot as a mobile map feature.

Dentral Crown: A dental crown system is a type of extracoronal restoration, or a restoration that exists around a remaining tooth structure. It is used in situations where there is not enough remaining solid tooth structure after decay or when a tooth has fractured and is missing important structural reinforcements. It typically consists of four layers, including the original tooth core, a layer of cement, a crown layer to provide the structural support, and a veneer layer that gives the look of a real tooth. All of these layers were created and assembled in order to accurately represent a crown system for the project. The goal of this project is to determine the effects of a temperature change on the maximum principle stress for the crown layer of the system. This helps determine how long the crown can be used before it will break. Temperature and stress analyses will be done for four different material combinations in order to see what effect these have on the system as well as what materials are better to use for a crown system. Hovercraft: A hovercraft is a special type of vehicle that moves on a cushion of air. The lifting motion is controlled by a fan or fans so that an air gap can be formed beneath the vehicle. Such separation between the bottom of the hovercraft and the ground provides a motion platform, on which the friction force between the hovercraft and the ground reduces to a very small amount. Since a hovercraft does not have wheels, the forward motion is created through propulsion, which is generated by the use of a fan or set of fans located on the back end of the hovercraft. These propulsion fans send the air backward to produce a thrust force, which moves the hovercraft forward. The goal of this project is to analyze, create, and control a working hovercraft model. Initially, flow analysis will be performed on a hovercraft model created in SolidWorks. After a design has been found that provides the necessary lift force, the model will be construct

It has been known for some time that the classical work of Kirchhoff, Love,and Birkhoff on rigid bodies in incompressible, irrotational flows provideseffective models for treating control problems for underwater vehicles.This has also led to a better appreciation of the dynamics of suchsystems. In this paper, we develop results based on geometric mechanics andcenter manifold theory to solve controllability and stabilization questionsfor a class of under-actuated left invariant mechanical systems on Liegroups that include approximate models of underwater vehicles and surfacevehicles. We also provide numerical evidence to capture the globalproperties of certain interesting feedback laws.(This work appears as an invited paper in the Proc. IFAC Sympo. on NonlinearControl Systems Design (NOLCOS'98), (1998), 1:139-144)

The focus of this dissertation is to study issues related to controllability and stabilization of a class of underactuated mechanical systems with symmetry. In particular we look at systems whose configuration can be identified with a Lie group and the reduced equations are of the Lie-Poisson type. Examples of such systems include hovercraft, spacecraft and autonomous underwater vehicles. We present sufficient conditions for the controllability of affine nonlinear control systems where the drift vector field is a Lie-Poisson reduced Hamiltonian vector field. In this setting we show that depending on the existence of a radially unbounded Lyapunov type function, the drift vector field of the reduced system is weakly positively Poisson stable. The weak positive Poisson stability along with the Lie algebra rank condition is used to show controllability. These controllability results are then extended to the unreduced dynamics. Sufficient conditions for controllability are presented in both cases where the symmetry group is compact and noncompact. We also present a constructive approach to design feedback laws to stabilize relative equilibria of these systems. The approach is based on the observation that, under certain hypotheses the fixed points of the Lie-Poisson dynamics belong to an immersed equilibrium submanifold. The existence of such equilibrium manifolds, along with the center manifold theory is used to design stabilizing feedback laws.

The focus of this dissertation is to study issues related to controllability and stabilization of a class of underactuated mechanical systems with symmetry. In particular we look at systems whose configuration can be identified with a Lie group and the reduced equations are of the Lie-Poisson type. Examples of such systems include hovercraft, spacecraft and autonomous underwater vehicles. We present sufficient conditions for the controllability of affine nonlinear control systems where the drift vector field is a Lie-Poisson reduced Hamiltonian vector field. In this setting we show that depending on the existence of a radially unbounded Lyapunov type function, the drift vector field of the reduced system is weakly positively Poisson stable. The weak positive Poisson stability along with the Lie algebra rank condition is used to show controllability. These controllability results are then extended to the unreduced dynamics. Sufficient conditions for controllability are presented in both cases where the symmetry group is compact and noncompact. We also present a constructive approach to design feedback laws to stabilize relative equilibria of these systems. The approach is based on the observation that, under certain hypotheses the fixed points of the Lie-Poisson dynamics belong to an immersed equilibrium submanifold. The existence of such equilibrium manifolds, along with the center manifold theory is used to design stabilizing feedback laws.

In this paper we present sufficient conditions for controllability of Lie-Poisson reduced dynamics of a class of mechanical systems with symmetry. We prove conditions (boundedness of coadjoint orbits and existence of a radially unbounded Lyapunov function) under which the drift vector field (of the reduced system) is weakly positively Poisson stable (WPPS). The WPPS nature of the drift vector field along with the Lie algebra rank condition is used to show controllability of the reduced system. We discuss the dynamics, Lie-Poisson reduction, and controllability of hovercraft, spacecraft and underwater vehicles, all treated as rigid bodies.

This paper presents the background to the development of composite materials in marine structures in the Scandinavian countries. The very first vessel constructed in composite materials in 1974 used a special sandwich technique, GRP sandwich, developed in Sweden. Since the the GRP sandwich technique has been the only ship hull construction method used in the Scandinavian countries. The construction method is briefly described, together with the material used. In the second part of the paper examples of the different types of vessels under construction are presented. Finally, in the conclusion some ideas of future development are outlined., Nous présentons l'expérience du développement des matériaux composites pour les structures marines dans les pays Scandinaves. Le premier navire construit en matériaux composites en 1974, utilisait une technique sandwich spéciale, le sandwich GRP, développée en Suède. Depuis, la technique du sandwich GRP a été la seule utilisée pour la construction de coque par les pays Scandinaves. La méthode de construction est décrite brièvement, ainsi que le matériau utilisé. Ensuite, des exemples de différents types de navires en construction sont présentés. Enfin, quelques idées de développements futurs sont exposées.

This paper deals with the structural analysis of transverse frames and bulkheads in sandwich catamarans. Finite element analyses of a frame and a bulkhead have been carried out, and the results are compared to those obtained from a finite element model of the entire craft. The frame and the bulkhead have been analysed with five different boundary conditions. Four idealized load combinations have been applied, and it is demonstrated that transverse frame models can give quite inaccurate results. This is due to the difficulty in deciding the relevant support springs to represent the interaction between the actual frame and the other part of the structure. When designing a new type of vessel, it is recommended to carry out a global finite element analysis instead of relying on frame models., Cet article traite de l'analyse structurale des cadres et cloisons transversaux d'un catamaran en sandwich. Des analyses par éléments finis d'un cadre et d'une cloison ont été menées, et les résultats sont comparés à ceux obtenus à partir d'un modèle par éléments finis pour le navire tout entier. Le cadre et la cloison ont été analysés avec cinq conditions limites différentes. Quatre combinaisons de charge idéalisées ont été appliquées, et on a démontré que les modèles de cadres transversaux peuvent donner des résultats inexacts. Ceci est dû à la difficulté de choisir le montage de ressorts adéquat pour représenter l'interaction entre le cadre lui-même et les autres parties de la structure. Pour concevoir un nouveau type de bateau, il est recommandé de mener une analyse globale par éléments finis au lieu de s'appuyer sur les modèles de cadres.

This paper is an overview of what has been done in the area of FRP-sandwich in the maritime industry over the last 15 years. The advantages of building in FRP-sandwich will be discussed with regards to past production methods and applications into other markets. Since the late sixties the development and use of light and strong construction materials and new construction methods has increased. The use of Fibre Reinforced Plastic (FRP)-sandwich has successfully been introduced to a variety of areas. Barracuda Technologies has over the years tried to fullfil customers' demands by developing new and better foam cores and adhesives and new improved production methods. The result of this is that we now supply Divinycell, a sandwich core, and Divilette, an adhesive, to a large number of different areas: aviation, railroad, trucks, vessels, sea trucks, etc. This paper will not go into the details of the use of FRP-sandwich, but is meant as an overview of what has happened, and what is to come in this area., Cet article passe en revue ce qui a été fait dans le domaine des sandwichs FRP dans l'industrie maritime ces 15 dernières années. Les avantages de la construction en sandwich FRP seront discutés par rapport aux méthodes de production passées et aux applications pour d'autres marchés. Depuis la fin des années soixante, le développement et l'utilisation de matériaux de construction légers et résistants, ainsi que des nouvelles méthodes de construction ont augmenté. L'utilisation de sandwich-plastique renforcé par fibres (FRP) a été introduite avec succès dans de nombreux domaines. Barracuda Technologies a essayé de satisfaire la demande des clients en développant des âmes en mousse nouvelles et meilleures et des adhésifs, ainsi qu'en perfectionnant les méthodes de production. Le résultat de tout ceci est Divinycell, une âme domaines : aviation, chemin de fer, camions, navires, camions des mers, etc. Cet article ne décrit pas en détail l'utilisation du sandwich-FRP, mais a pour objet une vue générale de ce qui s'est passé, et de ce qui se passera dans ce domaine.

This paper presents the background to the development of composite materials in marine structures in the Scandinavian countries. The very first vessel constructed in composite materials in 1974 used a special sandwich technique, GRP sandwich, developed in Sweden. Since the the GRP sandwich technique has been the only ship hull construction method used in the Scandinavian countries. The construction method is briefly described, together with the material used. In the second part of the paper examples of the different types of vessels under construction are presented. Finally, in the conclusion some ideas of future development are outlined., Nous présentons l'expérience du développement des matériaux composites pour les structures marines dans les pays Scandinaves. Le premier navire construit en matériaux composites en 1974, utilisait une technique sandwich spéciale, le sandwich GRP, développée en Suède. Depuis, la technique du sandwich GRP a été la seule utilisée pour la construction de coque par les pays Scandinaves. La méthode de construction est décrite brièvement, ainsi que le matériau utilisé. Ensuite, des exemples de différents types de navires en construction sont présentés. Enfin, quelques idées de développements futurs sont exposées.

This paper deals with the structural analysis of transverse frames and bulkheads in sandwich catamarans. Finite element analyses of a frame and a bulkhead have been carried out, and the results are compared to those obtained from a finite element model of the entire craft. The frame and the bulkhead have been analysed with five different boundary conditions. Four idealized load combinations have been applied, and it is demonstrated that transverse frame models can give quite inaccurate results. This is due to the difficulty in deciding the relevant support springs to represent the interaction between the actual frame and the other part of the structure. When designing a new type of vessel, it is recommended to carry out a global finite element analysis instead of relying on frame models., Cet article traite de l'analyse structurale des cadres et cloisons transversaux d'un catamaran en sandwich. Des analyses par éléments finis d'un cadre et d'une cloison ont été menées, et les résultats sont comparés à ceux obtenus à partir d'un modèle par éléments finis pour le navire tout entier. Le cadre et la cloison ont été analysés avec cinq conditions limites différentes. Quatre combinaisons de charge idéalisées ont été appliquées, et on a démontré que les modèles de cadres transversaux peuvent donner des résultats inexacts. Ceci est dû à la difficulté de choisir le montage de ressorts adéquat pour représenter l'interaction entre le cadre lui-même et les autres parties de la structure. Pour concevoir un nouveau type de bateau, il est recommandé de mener une analyse globale par éléments finis au lieu de s'appuyer sur les modèles de cadres.

This paper is an overview of what has been done in the area of FRP-sandwich in the maritime industry over the last 15 years. The advantages of building in FRP-sandwich will be discussed with regards to past production methods and applications into other markets. Since the late sixties the development and use of light and strong construction materials and new construction methods has increased. The use of Fibre Reinforced Plastic (FRP)-sandwich has successfully been introduced to a variety of areas. Barracuda Technologies has over the years tried to fullfil customers' demands by developing new and better foam cores and adhesives and new improved production methods. The result of this is that we now supply Divinycell, a sandwich core, and Divilette, an adhesive, to a large number of different areas: aviation, railroad, trucks, vessels, sea trucks, etc. This paper will not go into the details of the use of FRP-sandwich, but is meant as an overview of what has happened, and what is to come in this area., Cet article passe en revue ce qui a été fait dans le domaine des sandwichs FRP dans l'industrie maritime ces 15 dernières années. Les avantages de la construction en sandwich FRP seront discutés par rapport aux méthodes de production passées et aux applications pour d'autres marchés. Depuis la fin des années soixante, le développement et l'utilisation de matériaux de construction légers et résistants, ainsi que des nouvelles méthodes de construction ont augmenté. L'utilisation de sandwich-plastique renforcé par fibres (FRP) a été introduite avec succès dans de nombreux domaines. Barracuda Technologies a essayé de satisfaire la demande des clients en développant des âmes en mousse nouvelles et meilleures et des adhésifs, ainsi qu'en perfectionnant les méthodes de production. Le résultat de tout ceci est Divinycell, une âme domaines : aviation, chemin de fer, camions, navires, camions des mers, etc. Cet article ne décrit pas en détail l'utilisation du sandwich-FRP, mais a pour objet une vue générale de ce qui s'est passé, et de ce qui se passera dans ce domaine.

This paper deals with the structural analysis of transverse frames and bulkheads in sandwich catamarans. Finite element analyses of a frame and a bulkhead have been carried out, and the results are compared to those obtained from a finite element model of the entire craft. The frame and the bulkhead have been analysed with five different boundary conditions. Four idealized load combinations have been applied, and it is demonstrated that transverse frame models can give quite inaccurate results. This is due to the difficulty in deciding the relevant support springs to represent the interaction between the actual frame and the other part of the structure. When designing a new type of vessel, it is recommended to carry out a global finite element analysis instead of relying on frame models., Cet article traite de l'analyse structurale des cadres et cloisons transversaux d'un catamaran en sandwich. Des analyses par éléments finis d'un cadre et d'une cloison ont été menées, et les résultats sont comparés à ceux obtenus à partir d'un modèle par éléments finis pour le navire tout entier. Le cadre et la cloison ont été analysés avec cinq conditions limites différentes. Quatre combinaisons de charge idéalisées ont été appliquées, et on a démontré que les modèles de cadres transversaux peuvent donner des résultats inexacts. Ceci est dû à la difficulté de choisir le montage de ressorts adéquat pour représenter l'interaction entre le cadre lui-même et les autres parties de la structure. Pour concevoir un nouveau type de bateau, il est recommandé de mener une analyse globale par éléments finis au lieu de s'appuyer sur les modèles de cadres.

This paper presents the background to the development of composite materials in marine structures in the Scandinavian countries. The very first vessel constructed in composite materials in 1974 used a special sandwich technique, GRP sandwich, developed in Sweden. Since the the GRP sandwich technique has been the only ship hull construction method used in the Scandinavian countries. The construction method is briefly described, together with the material used. In the second part of the paper examples of the different types of vessels under construction are presented. Finally, in the conclusion some ideas of future development are outlined., Nous présentons l'expérience du développement des matériaux composites pour les structures marines dans les pays Scandinaves. Le premier navire construit en matériaux composites en 1974, utilisait une technique sandwich spéciale, le sandwich GRP, développée en Suède. Depuis, la technique du sandwich GRP a été la seule utilisée pour la construction de coque par les pays Scandinaves. La méthode de construction est décrite brièvement, ainsi que le matériau utilisé. Ensuite, des exemples de différents types de navires en construction sont présentés. Enfin, quelques idées de développements futurs sont exposées.

This paper is an overview of what has been done in the area of FRP-sandwich in the maritime industry over the last 15 years. The advantages of building in FRP-sandwich will be discussed with regards to past production methods and applications into other markets. Since the late sixties the development and use of light and strong construction materials and new construction methods has increased. The use of Fibre Reinforced Plastic (FRP)-sandwich has successfully been introduced to a variety of areas. Barracuda Technologies has over the years tried to fullfil customers' demands by developing new and better foam cores and adhesives and new improved production methods. The result of this is that we now supply Divinycell, a sandwich core, and Divilette, an adhesive, to a large number of different areas: aviation, railroad, trucks, vessels, sea trucks, etc. This paper will not go into the details of the use of FRP-sandwich, but is meant as an overview of what has happened, and what is to come in this area., Cet article passe en revue ce qui a été fait dans le domaine des sandwichs FRP dans l'industrie maritime ces 15 dernières années. Les avantages de la construction en sandwich FRP seront discutés par rapport aux méthodes de production passées et aux applications pour d'autres marchés. Depuis la fin des années soixante, le développement et l'utilisation de matériaux de construction légers et résistants, ainsi que des nouvelles méthodes de construction ont augmenté. L'utilisation de sandwich-plastique renforcé par fibres (FRP) a été introduite avec succès dans de nombreux domaines. Barracuda Technologies a essayé de satisfaire la demande des clients en développant des âmes en mousse nouvelles et meilleures et des adhésifs, ainsi qu'en perfectionnant les méthodes de production. Le résultat de tout ceci est Divinycell, une âme domaines : aviation, chemin de fer, camions, navires, camions des mers, etc. Cet article ne décrit pas en détail l'utilisation du sandwich-FRP, mais a pour objet une vue générale de ce qui s'est passé, et de ce qui se passera dans ce domaine.

This paper is an overview of what has been done in the area of FRP-sandwich in the maritime industry over the last 15 years. The advantages of building in FRP-sandwich will be discussed with regards to past production methods and applications into other markets. Since the late sixties the development and use of light and strong construction materials and new construction methods has increased. The use of Fibre Reinforced Plastic (FRP)-sandwich has successfully been introduced to a variety of areas. Barracuda Technologies has over the years tried to fullfil customers' demands by developing new and better foam cores and adhesives and new improved production methods. The result of this is that we now supply Divinycell, a sandwich core, and Divilette, an adhesive, to a large number of different areas: aviation, railroad, trucks, vessels, sea trucks, etc. This paper will not go into the details of the use of FRP-sandwich, but is meant as an overview of what has happened, and what is to come in this area., Cet article passe en revue ce qui a été fait dans le domaine des sandwichs FRP dans l'industrie maritime ces 15 dernières années. Les avantages de la construction en sandwich FRP seront discutés par rapport aux méthodes de production passées et aux applications pour d'autres marchés. Depuis la fin des années soixante, le développement et l'utilisation de matériaux de construction légers et résistants, ainsi que des nouvelles méthodes de construction ont augmenté. L'utilisation de sandwich-plastique renforcé par fibres (FRP) a été introduite avec succès dans de nombreux domaines. Barracuda Technologies a essayé de satisfaire la demande des clients en développant des âmes en mousse nouvelles et meilleures et des adhésifs, ainsi qu'en perfectionnant les méthodes de production. Le résultat de tout ceci est Divinycell, une âme domaines : aviation, chemin de fer, camions, navires, camions des mers, etc. Cet article ne décrit pas en détail l'utilisation du sandwich-FRP, mais a pour objet une vue générale de ce qui s'est passé, et de ce qui se passera dans ce domaine.

This paper deals with the structural analysis of transverse frames and bulkheads in sandwich catamarans. Finite element analyses of a frame and a bulkhead have been carried out, and the results are compared to those obtained from a finite element model of the entire craft. The frame and the bulkhead have been analysed with five different boundary conditions. Four idealized load combinations have been applied, and it is demonstrated that transverse frame models can give quite inaccurate results. This is due to the difficulty in deciding the relevant support springs to represent the interaction between the actual frame and the other part of the structure. When designing a new type of vessel, it is recommended to carry out a global finite element analysis instead of relying on frame models., Cet article traite de l'analyse structurale des cadres et cloisons transversaux d'un catamaran en sandwich. Des analyses par éléments finis d'un cadre et d'une cloison ont été menées, et les résultats sont comparés à ceux obtenus à partir d'un modèle par éléments finis pour le navire tout entier. Le cadre et la cloison ont été analysés avec cinq conditions limites différentes. Quatre combinaisons de charge idéalisées ont été appliquées, et on a démontré que les modèles de cadres transversaux peuvent donner des résultats inexacts. Ceci est dû à la difficulté de choisir le montage de ressorts adéquat pour représenter l'interaction entre le cadre lui-même et les autres parties de la structure. Pour concevoir un nouveau type de bateau, il est recommandé de mener une analyse globale par éléments finis au lieu de s'appuyer sur les modèles de cadres.

This paper presents the background to the development of composite materials in marine structures in the Scandinavian countries. The very first vessel constructed in composite materials in 1974 used a special sandwich technique, GRP sandwich, developed in Sweden. Since the the GRP sandwich technique has been the only ship hull construction method used in the Scandinavian countries. The construction method is briefly described, together with the material used. In the second part of the paper examples of the different types of vessels under construction are presented. Finally, in the conclusion some ideas of future development are outlined., Nous présentons l'expérience du développement des matériaux composites pour les structures marines dans les pays Scandinaves. Le premier navire construit en matériaux composites en 1974, utilisait une technique sandwich spéciale, le sandwich GRP, développée en Suède. Depuis, la technique du sandwich GRP a été la seule utilisée pour la construction de coque par les pays Scandinaves. La méthode de construction est décrite brièvement, ainsi que le matériau utilisé. Ensuite, des exemples de différents types de navires en construction sont présentés. Enfin, quelques idées de développements futurs sont exposées.

A proposal has been made to compute a 2-D numerical solution to the stream function - vorticity equation to analyze the flow field, both of an airfoil in ground effect and of an air cushion vehicle of arbitrary geometry supported by peripheral jets. This report is an investigation of both problems. Finite difference solutions of the stream function-vorticity equation are computed on a body fitted coordinate system. The Laplace equation for streamlines around an airfoil in ground effect is solved, and results are compared to an analytic finite singularity solution. Comparison of Cl and Cma.c at varying angles of attack and ground distance indicate good agreement. The finite difference method is found to be sensitive to grid point distribution about the leading edge, for which a criterion is established. Since an air cushion vehicle acts as a flow source within the field, the finite difference expression is modified to accommodate a branch cut. The presence of vorticity is essential to definition of the peripheral jets. The vorticity distribution, derived from arbitrary velocity distribution at jet outlets and assumed to be constant along streamlines, leads to a stable solution of the stream function- vorticity equation., Personally Identifiable Information (PII) was redacted.

Contains several articles including topics on wrap-around antennas, SRN3 Hovercraft, training and research, statistics and reliability, and book reviews, notes and news, retirements and obituaries.

Vehicles in the class of surface effect ships (SES) and air cushion vehicles (ACV) respond to airblast loading in a manner different from that of conventional displacement-type ships. The SES/ACV class of vehicles has low hydrodynamic drag resistance to motion response and the air cushion chamber which levitates the vehicles can interact with the blast wave. The rigid body response of a hovercraft (ACV) in an airblast environment was investigated by conducting free field HE explosive tests. The airblast loading was of short duration (25-35 msec free field positive phase). The results are discussed.

Hydrodynamic tests were conducted on a model of the FSACV to characterize the craft in the areas of performance, seakeeping, habitability and stability. Data was obtained over a range of LCG's trunk pressures, speeds, and cushion air flows in both calm water and irregular head seas. The results are tabulated and graphed, and the effect of major parameters discussed. (Author)

This report is based on a lecture series presented by the authors in May and July 1965. The lectures were prepared under the joint auspices of the David Taylor Model Basin and the Naval Air Development Center. The revised lectures include: (1) Air Cushion Mechanics; (2) Internal Aerodynamics; (3) Drag; (4) Cushion Contributions to Stability; and (5) Seakeeping., See also AD-635 512, AD-635 468, AD-636 099, AD-636 277, AD-653 859 and AD-640 015 for individual sections.

The laser Doppler technique has been applied to determine the aerodynamic wake velocity components behind a tethered air cushion vehicle (ACV) which runs close to a confining wall. Two velocity components were measured for a number of locations behind the vehicle, using the fringe mode and forward scattering from unseeded air. Some auxiliary forward and back scatter experiments with pulsed and D C lasers are also described. A video tape recorder was used to record all the laser Doppler data, which could then be processed by an oscilloscope, a spectrum analyzes or a DISA 55L signal processor. Results are presented which show that the stabilized wake effects are minimal for UTIAS ACV and its associated facility. (Author)

This report summarizes the advances in understanding of the Arctic which have come about since the inception of the ARPA Arctic Surface Effect Vehicle Program in 1970, primarily as the result of CRREL's participation. Major efforts to increase knowledge of sea ice, terrestrial, and coastal topographic features are described. Special emphasis is placed upon the quantitative understanding of pressure ridging. Other areas of major interest are atmospheric characteristics and ecological effects. A list of publications generated is included., Also available as Chapter 2 of the Arctic Surface Effect Vehicle Program Technology Summary Document, Volume 2.

This report catalogues high performance watercraft and their capabilities for Coast Guard personnel. It provides general operational and technical information regarding hydrofoils, hovercraft, mono-hull and multi-hull high performance vehicles and is divided into three sections for ease of reference. The first section deals with the technical and operational characteristics of the generic craft themselves while the second section compares craft capabilities. The third section abstracts available HPWC literature.

V diplomové práci se zabývám návrhem vznášedla, spadajícího do kategorie lehkých strojů. Vznášedlo je svou koncepcí určeno pro rekreační, případně výzkumné využití. Interiér kabiny je uzpůsoben pro obsazení 5-člennou posádkou, popř. nákladem do cca 600 kg. Práce je věnována celkové koncepci exteriéru vznášedla, jsou zde však naznačena řešení některých uzlových bodů v interiéru, a to především z hlediska ergonomie. Výsledkem této práce je vytvoření originálního designu stroje a to za použití současných technických řešení a materiálů., Diploma thesis deals with the developement of hovercraft prototype. Hovercraft is generally included into the category of light appliances. It is considered as a appliance for vacation or experimental utilisation. Interior is customised for 5 member crew or else up to 600 kg of loading. Diploma thesis is focused on the exterior of the hovercraf, hence there are mentioned solutions of selected node points in interior with a view to the ergonomic features. There is an outcome of original design combined with modern technological solutions and materials in this diploma thesis project.

V diplomové práci se věnuji návrhu designu vznášedla. Koncepce návrhu je malé vznášedlo pro osobní přepravu. Stylem vznášedlo zapadá mezi sportovní stroje. Interiér je navržen pro přepravu 4 osob a osobního nákladu. Hlavní náplní práce je exteriér vznášedla. Její součástí je ale i nástin řešení interiéru v základních rozměrech odpovídajícím antropometrickým rozměrům a jiným ergonomickým požadavkům.Výsledkem tedy je originální a osobité vznášedlo, které je vyřešeno z hlediska designu s ohledem na ergonomii a technologická omezení, která vznášedla přináší., The Diploma thesis is dedicated to design of a hovercraft. The concept of design is a small hovercraft for personal use. The hovercraft is styled into a sports category. The interior is designed for 4 persons and personal luggage. Main part of the work is the exterior of the hovercraft. But it contains also a basic vision of interior solution with basic dimensions according to antropometric measures and other ergonomical criteria. So the result is original hovercraft, which is solved in area of design with regards for ergonomics and technological limitations, which hovercraft brings.

V diplomové práci se zabývám návrhem vznášedla, spadajícího do kategorie lehkých strojů. Vznášedlo je svou koncepcí určeno pro rekreační, případně výzkumné využití. Interiér kabiny je uzpůsoben pro obsazení 5-člennou posádkou, popř. nákladem do cca 600 kg. Práce je věnována celkové koncepci exteriéru vznášedla, jsou zde však naznačena řešení některých uzlových bodů v interiéru, a to především z hlediska ergonomie. Výsledkem této práce je vytvoření originálního designu stroje a to za použití současných technických řešení a materiálů., Diploma thesis deals with the developement of hovercraft prototype. Hovercraft is generally included into the category of light appliances. It is considered as a appliance for vacation or experimental utilisation. Interior is customised for 5 member crew or else up to 600 kg of loading. Diploma thesis is focused on the exterior of the hovercraf, hence there are mentioned solutions of selected node points in interior with a view to the ergonomic features. There is an outcome of original design combined with modern technological solutions and materials in this diploma thesis project.

V diplomové práci se zabývám návrhem vznášedla, spadajícího do kategorie lehkých strojů. Vznášedlo je svou koncepcí určeno pro rekreační, případně výzkumné využití. Interiér kabiny je uzpůsoben pro obsazení 5-člennou posádkou, popř. nákladem do cca 600 kg. Práce je věnována celkové koncepci exteriéru vznášedla, jsou zde však naznačena řešení některých uzlových bodů v interiéru, a to především z hlediska ergonomie. Výsledkem této práce je vytvoření originálního designu stroje a to za použití současných technických řešení a materiálů., Diploma thesis deals with the developement of hovercraft prototype. Hovercraft is generally included into the category of light appliances. It is considered as a appliance for vacation or experimental utilisation. Interior is customised for 5 member crew or else up to 600 kg of loading. Diploma thesis is focused on the exterior of the hovercraf, hence there are mentioned solutions of selected node points in interior with a view to the ergonomic features. There is an outcome of original design combined with modern technological solutions and materials in this diploma thesis project.

V diplomové práci se zabývám návrhem vznášedla, spadajícího do kategorie lehkých strojů. Vznášedlo je svou koncepcí určeno pro rekreační, případně výzkumné využití. Interiér kabiny je uzpůsoben pro obsazení 5-člennou posádkou, popř. nákladem do cca 600 kg. Práce je věnována celkové koncepci exteriéru vznášedla, jsou zde však naznačena řešení některých uzlových bodů v interiéru, a to především z hlediska ergonomie. Výsledkem této práce je vytvoření originálního designu stroje a to za použití současných technických řešení a materiálů., Diploma thesis deals with the developement of hovercraft prototype. Hovercraft is generally included into the category of light appliances. It is considered as a appliance for vacation or experimental utilisation. Interior is customised for 5 member crew or else up to 600 kg of loading. Diploma thesis is focused on the exterior of the hovercraf, hence there are mentioned solutions of selected node points in interior with a view to the ergonomic features. There is an outcome of original design combined with modern technological solutions and materials in this diploma thesis project.

V diplomové práci se věnuji návrhu designu vznášedla. Koncepce návrhu je malé vznášedlo pro osobní přepravu. Stylem vznášedlo zapadá mezi sportovní stroje. Interiér je navržen pro přepravu 4 osob a osobního nákladu. Hlavní náplní práce je exteriér vznášedla. Její součástí je ale i nástin řešení interiéru v základních rozměrech odpovídajícím antropometrickým rozměrům a jiným ergonomickým požadavkům.Výsledkem tedy je originální a osobité vznášedlo, které je vyřešeno z hlediska designu s ohledem na ergonomii a technologická omezení, která vznášedla přináší., The Diploma thesis is dedicated to design of a hovercraft. The concept of design is a small hovercraft for personal use. The hovercraft is styled into a sports category. The interior is designed for 4 persons and personal luggage. Main part of the work is the exterior of the hovercraft. But it contains also a basic vision of interior solution with basic dimensions according to antropometric measures and other ergonomical criteria. So the result is original hovercraft, which is solved in area of design with regards for ergonomics and technological limitations, which hovercraft brings.

V diplomové práci se věnuji návrhu designu vznášedla. Koncepce návrhu je malé vznášedlo pro osobní přepravu. Stylem vznášedlo zapadá mezi sportovní stroje. Interiér je navržen pro přepravu 4 osob a osobního nákladu. Hlavní náplní práce je exteriér vznášedla. Její součástí je ale i nástin řešení interiéru v základních rozměrech odpovídajícím antropometrickým rozměrům a jiným ergonomickým požadavkům.Výsledkem tedy je originální a osobité vznášedlo, které je vyřešeno z hlediska designu s ohledem na ergonomii a technologická omezení, která vznášedla přináší., The Diploma thesis is dedicated to design of a hovercraft. The concept of design is a small hovercraft for personal use. The hovercraft is styled into a sports category. The interior is designed for 4 persons and personal luggage. Main part of the work is the exterior of the hovercraft. But it contains also a basic vision of interior solution with basic dimensions according to antropometric measures and other ergonomical criteria. So the result is original hovercraft, which is solved in area of design with regards for ergonomics and technological limitations, which hovercraft brings.

V diplomové práci se zabývám návrhem vznášedla, spadajícího do kategorie lehkých strojů. Vznášedlo je svou koncepcí určeno pro rekreační, případně výzkumné využití. Interiér kabiny je uzpůsoben pro obsazení 5-člennou posádkou, popř. nákladem do cca 600 kg. Práce je věnována celkové koncepci exteriéru vznášedla, jsou zde však naznačena řešení některých uzlových bodů v interiéru, a to především z hlediska ergonomie. Výsledkem této práce je vytvoření originálního designu stroje a to za použití současných technických řešení a materiálů., Diploma thesis deals with the developement of hovercraft prototype. Hovercraft is generally included into the category of light appliances. It is considered as a appliance for vacation or experimental utilisation. Interior is customised for 5 member crew or else up to 600 kg of loading. Diploma thesis is focused on the exterior of the hovercraf, hence there are mentioned solutions of selected node points in interior with a view to the ergonomic features. There is an outcome of original design combined with modern technological solutions and materials in this diploma thesis project.

V diplomové práci se zabývám návrhem vznášedla, spadajícího do kategorie lehkých strojů. Vznášedlo je svou koncepcí určeno pro rekreační, případně výzkumné využití. Interiér kabiny je uzpůsoben pro obsazení 5-člennou posádkou, popř. nákladem do cca 600 kg. Práce je věnována celkové koncepci exteriéru vznášedla, jsou zde však naznačena řešení některých uzlových bodů v interiéru, a to především z hlediska ergonomie. Výsledkem této práce je vytvoření originálního designu stroje a to za použití současných technických řešení a materiálů., Diploma thesis deals with the developement of hovercraft prototype. Hovercraft is generally included into the category of light appliances. It is considered as a appliance for vacation or experimental utilisation. Interior is customised for 5 member crew or else up to 600 kg of loading. Diploma thesis is focused on the exterior of the hovercraf, hence there are mentioned solutions of selected node points in interior with a view to the ergonomic features. There is an outcome of original design combined with modern technological solutions and materials in this diploma thesis project.

The U.S. Postal Service (USPS) proposes to transport bypass and non-priority mail by hovercraft (also known as air cushioned vehecles) on a year-round basis from the city of Bethel to nine Alaskan villages alon teh Kuskokwin, Johnson, and Pikmiktalik rivers. To optimize the hovercraft mail transport activity and satisfy bypass and non-priority mail service standards, transport of bypass and non-priority mail by hovercraft wuold be supplemented, as needed, with alternate modes of transportation such as trucks, snow machines, all terrain vehicles, boats, and planes. The project is needed to assist the USPS in meeting its mission in the Bethel area, which is to provide prompt, reliable, and efficient postal service within mail service standards. Specifically, a proven method to transport bypass and non-priority mail to rural areas surrounding Bethel is needed that will economically satisfy mail service standards.

VR663/N6083, During the period, June 1995 through March 1996, the U.S. Department of Transportation, Research and Special Programs Administration, John A. Volpe National Transportation, Systems Center (Volpe Center), Acoustics Facility, in support of the United States Postal, Service (Postal Service) Office of Environmental Policy & Management, conducted a Noise, Characterization Study of the British Hovercraft Corporation Model AP.1-88 Hovercraft, (AP.1-88). This document presents the results of the study, including the measurement, data reduction and analysis procedures used to characterize the craft. Also presented, for the purpose of comparison with the AP.1-88 noise data, is a limited amount of measured, noise data for the Textron Marine & Land Systems Lighter Air Cushion Vehicle-30 (LACV-30), hovercraft.

This report presents the results of the technology and safety assessment of the Bethel/Kuskokwim River hovercraft service,operated by the Alaska Hovercraft Joint Venture (AHJV). The primary purpose of the service was a two-year demonstration of bypass mail transport for the United States Postal Service (USPS).

The United States Postal Service (USPS) received an unsolicited proposal from Alaska Hovercraft Joint Venture for a two-year demonstration program for the transport of, bypass and non-priority mail by Hovercraft on a year-round basis from the city of Bethel to eight remote Alaskan villages. The demonstration program evaluated the merits of using a, Hovercraft to replace fixed wing airplanes to reliably transport mail., Implementing an alternative marine transportation mode in the remote regions of Alaska is not only technically challenging, but environmental regulations and traditional and cultural belief present additional complexities. This paper provides a case study that outlines, some of the critical regulatory and social challenges faced by the project proponents and, the options that help with the successful implementation of a unique alternative mode of, marine transport.