Application of Cubic B-Spline Curves for Hull Meshing

This paper describes the development of a regular hull meshing code using cubic B-Spline curves. The discretization procedure begins by the definition of B-Spline curves over stations, bow and stern contours of the hull plan lines. Thus, new knots are created applying an equal spaced subdivision procedure on defined B-spline curves. Then, over these equal transversal space knots, longitudinal B-spline curves are defined and subdivided into equally spaced knots, too. Subsequently, new transversal knots are created using the longitudinal equally spaced knots. Finally, the hull mesh is composed by quadrilateral panels formed by these new transversal and longitudinal knots. This procedure is applied in the submerged Wigley hulls Series 60 Cb=0.60. Their mesh volumes are calculated using the divergence theorem, for mesh quality evaluation.

Analysis of integrated logistics support (ILS) in the shipbuilding industry. Advantages and improvement opportunities for the naval industry. COTECMAR case study

Integrated Logistics Support (ILS) applied in the world-class shipbuilding industry has set significant trends in the processes and life cycles of the products and/or systems developed. COTECMAR as a Countrywide pioneer company in this sector, with specific strengths in naval prototypes, has been developing actions together with the National Navy to integrate concepts related to ILS, in its processes. Therefore, a detailed analysis of how these processes are facing the requirements of such support, has become necessary, starting from the initial basis of the possible advantages and opportunities for improvement that this could bring to the corporation and the sector. This is based on the theoretical and conceptual foundations in the ILS framework and how these are developed in the company under analysis.

Conceptual design of coastal patrol vessel (CPV) with flight deck for the reception and deployment of helicopter

This paper presents the development of the conceptual design of a coastal Patrol vessel with the capacity to receive and deploy a helicopter, in order to increase the efficiency of coastguard operations developed by the Colombian National Navy. As a starting point, the design of the coastal patrol vessel built by Cotecmar and named CPV46 was taken, on which modifications were implemented in its main dimensions and distribution of spaces, which allowed to include a flight deck to receive a BELL 412 EP helicopter, complying with the regulations for this type of operations.This design was developed based on the design spiral method, where each turn of the spiral includes estimates and performance calculations influenced by each other and corresponding to the different stages of the design. For this work, the conceptual design was divided into eight booklets containing the state of the art, mission profile, capacity sizing, naval architecture, propeller selection, generator selection, stability study and cost estimation, concluding in the feasibility of the design based on its cost at a conceptual level.

Design of a marine propeller for scale racing boats in a speed and energy efficiency contest

The process of optimized design, evaluation and manufacturing of high energy efficiency propellers for competition boats at scale is addressed in this research. This project uses the stages of hydrodynamic design, numerical testing and manufacturing of four prototypes as example. During the hydrodynamic design, three design methodologies were compared, namely: Blade Element Theory, lifting line theory and design based on DTMB propeller series. The objective function of the optimized design is based on obtaining the chord and pitch distribution that generates the greatest thrust, speed and efficiency. Similarly, the performance of each prototype was evaluated by CFD in a virtual channel registering thrust, torque and speed. Finally, the additive manufacturing process applied is presented. Prototyped propellers present efficiencies and maximum speeds approximately 15% higher than recommended commercial propellers for this type of boats. This study was developed by the Hydrometra group in the framework of the international competition Hydrocontest 2017.

Analysis for use coastguard Offshore Platforms or SWATH Patrol Vessels in the Colombian Pacific Ocean

The average cocaine seizure rate of coast guard operations in the Colombian Pacific can be improved. To enhance this indicator, detection and interdiction must be improved. Therefore, the option of using an offshore platform with better detection means, and several Rapid Reasponse Units (RRUs) stationed offshore, is being analyzed. As a result, offshore platforms are neither feasible nor viable due to the depth of the sea floor (> 2 km), but SWATH platforms can be used. The parametric design of two SWATHs is performed and an operational evaluation is made of the different current units and SWATHs. The operational evaluation of the different current units and the proposed SWATHs is carried out and contrasted with their acquisition and life cycle cost, showing that the SWATHs have a better efficiency/cost ratio. Therefore, they can be considered as an alternative to improve the efficiency of cocaine seizures and other coast guard operations.

Design and Structural Analysis of a SWATH type vessel using the Finite Element Method and its response to Slamming events

The main objective of this study is to analyze the structural response of a boat during a slamming event using the Finite Element Method in a Small Water Area Twin Hull (SWATH) type boat. In the mentioned load condition, the acceptance criteria established by a classification society must be fulfilled, taking into account the areas where this event affects the structure such as the junction deck, the pontoons and other structural members established by the standard, all this generated by the high pressure loads in the ship's structure in a very short period of time being an element of study in this type of vessels, as long as they are within the range of high speed vessels. Among the main results of this study were the deformations and stresses in the structure obtained under the reference parameters of the classification society.

Calculation of the Specific Attenuation in Satellite Bands Due to the Rain in the City of Cartagena and its Importance in the Naval Field

This work studies the attenuation by rain that occurs in the Caribbean region, specifically, in high frequency bands, considering that modern communication systems make greater use of satellite bands. In this sense, the methodology of the recommendation ITU 838 was used to calculate the radio attenuation by rain in the city of Cartagena (Colombia), for the range of 1-100 GHz, and the data provided by the Center of Oceanographic and Hydrographic Research - CIOH were used as atmospheric information sources. As a result, the attenuation for the first quarter of the analyzed years was observed to be low (2.0x10-2 dB/km), growing in the following months until October (1.0x10-1 dB/km), when it decreases again. This information is particularly useful in the naval field, especially, in relation to the use of these frequencies for information exchange.

A Preliminary Study of Routing Protocols in a Tactical Data Link Ad Hoc Network in Colombian Maritime Scenario

Tactical Data Link (TDL) systems are a kind of Mobile Ad Hoc NETwork (MANET) used in diverse maritime operational environments such as natural disasters, surveillance, maritime search, and rescue. A TDL network is usually composed of nodes or units representing surface ships, submarines, and aircrafts able to participate in maritime operations. A routing protocol is required to establish communication between nodes, which guarantees the route from the source node to the destination node. A TDL has been developed in the Colombian Caribbean Sea (CTDL). However, no efficient routing protocol has been implemented. This works to perform a preliminary study to implement an appropriate routing protocol for the CTDL. Local environment constraints, in addition to the chosen protocols' performance analysis, will provide preliminary alternatives for a routing protocol with acceptable efficiency. This article provides a background of ad-hoc networks routing protocols, a description of the Colombian Caribbean maritime operational environment, a comparative analysis of routing protocols, and a discussion of conclusions and future developments regarding CTDL.

Jib crane bearing selection through simulation

Through the corrective maintenance process of a bearing, regardless of its origin, certain anomalies related to its main elements, due to the condition of the type of maintenance, are expected. This was the case of the jib crane of the Caribbean Submarine fleet, used mainly to load the wiring and charging sockets for the supply of electrical energy to the Submarines. During a routine operation, it malfunctioned and stopped working without warning. An inspection was carried out in which corrective maintenance was deemed necessary, it was at the time that the bearing support was uncovered and its advanced state of deterioration was observed. Being this the main failure, and through application of engineering principles and simulation software, the reason for the deterioration was determined, and the optimal bearings for the correct operation of the jib crane were selected.

Preliminary design of a management maintenance model of sensitive engineering assets, for a ship under the concept of reliability engineering

The objective of this research is to apply a dynamic maintenance model to the assets of the engineering department of a navy vessel, based on the concept of reliability engineering, which analyzes the statistics of failures of different equipment, in a period of 140 months, in order to determine which is the most sensible equipment, the failure modes and the impact it produces on the ship’s platform. This way, it is possible to focus on the problems that produce the biggest impact in the capacity of the Unit´s, in order to fulfill its roles, and this way, contribute increase its availability. This is an iterative process of continuous improvement for the maintenance plans.