The Design and Development of Modern Lifeboats

1993 ◽  
Vol 207 (1) ◽  
pp. 3-22 ◽  
Author(s):  
F D Hudson ◽  
I A Hicks ◽  
R M Cripps
Keyword(s):  
Construction Materials ◽  
Design Parameters ◽  
Impact Loads ◽  
Design And Development ◽  
Hull Form ◽  
Evaluation Procedures ◽  
History Of ◽  
Design Requirements ◽  
Operational Practices ◽  
Hull Forms

Well-established operational practices have determined the evolution of RNLI lifeboats throughout their history. The RNLI's requirement/or an all-fast offshore fleet of the self-righting type by 1993, however, motivated the need to re-examine basic design parameters of boats and launching equipment. More recent requirements to improve lifeboat performance further have demanded even closer evaluation of design requirements of hull form, machinery installation and construction materials. This paper outlines the history of the development of RNLI craft and describes the procedures for the design and development of its newest classes of lifeboat (FAB 3 and FAB 4), for which extensive model testing of differing hull forms was evaluated, various types of machinery were reviewed and construction, although in composite materials, was carefully designed to accommodate high hydrodynamic and impact loads. Technical trials and operational evaluation procedures are also discussed.

Analysis of Variance to Determine the Effect of Hull Form Parameters on Resistance and Seakeeping Performance for PSV Hulls

2016 ◽  
Author(s):  
Nicholas Boyd ◽  
David Molyneux
Keyword(s):  
Analysis Of Variance ◽  
Statistical Design ◽  
Design Parameters ◽  
Statistical Design Of Experiments ◽  
Hull Form ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Hull Design ◽  
Hull Forms ◽  
The Relationship

Throughout the world many Platform Supply Vessel designs have been proposed as the optimal form for their given operating environment, but evaluating these claims has been difficult due to a poor understanding of the relationships between hull form shapes and performance for these vessels. This paper presents the results of analysis aimed at determining these relationships. Results of CFD calculations to determine the Effective Horsepower/tonne for a series of PSV designs were presented in the paper A step towards an optimum PSV Hull form. This paper presents results for 16 separate hull forms, which were designed as each possible combination of four two-level hull form parameters. The hull form features considered were bow shape (vertical stem or bulbous), flat of bottom (flat or deadrise), length of parallel mid body (short or long), and stern shape (convention or integrated); resistance was calculated at two typical operating speeds (10 and 14 knots). This set of results was favourable for analysis using the statistical design of experiments technique: analysis of variance, which was used to determine the relationship between the hull and resistance performance. The same hull form series was used to study the effects of the hull form parameters on motions in head waves. A 2 level factorial experiment was designed based on the hull parameters with the heave and pitch response calculated using the potential flow ship motion prediction code Shipmo3D, for each of two representative wave conditions (summer light seas and winter heavy seas) at the zero speed and 10 knot operating speed. Analysis of variance was used to analyze the heave and pitch responses measured, and was used to determine the relationship between each hull parameter and each response. In both cases a 5% F-test was used to determine the significance of each parameter studied, and the significant effects were analyzed to determine their contributions to the overall model of the data. The results have found the relationships between the hull design parameters and the Effective Horespower/tonne, heave, and pitch response of the vessel, indicating which factors provide the largest contribution to minimizing each response. The interaction effects between factors were also examined to allow for a generalized understanding of the resulting effect of selecting one hull parameter over another. A numerical model combining all significant factors was fitted to the data, allowing for multiple objective optimization to determine which hull forms provide the most desirable performance for each response.

scholarly journals An Optimization Study on the Hull Form and Stern Appendage for Improving Resistance Performance of a Coastal Fishing Vessel

2021 ◽  
Vol 11 (13) ◽  
pp. 6124
Author(s):  
Jin-Won Yu ◽  
Min-Kyung Lee ◽  
Yang-Ik Kim ◽  
Sung-Bu Suh ◽  
Inwon Lee
Keyword(s):  
Fuel Efficiency ◽  
Variation Method ◽  
Design Parameters ◽  
Fishing Vessel ◽  
Hull Form ◽  
Fishing Vessels ◽  
Optimization Study ◽  
Principal Dimension ◽  
The Republic ◽  
Hull Forms

In response to the increasing number of free trade agreements (FTA) and the Trans-Pacific Partnership (TTP), it is necessary to develop next-generation fishing vessels for the littoral sea of the Republic of Korea. The main objectives of such fishing vessels are to enhance the comfort of the crew and to improve fuel efficiency under the newly established principal dimension. This paper employs the hull form variation method to obtain a series of forebody hull forms of the 19 gross tonnage class of a coastal composite fishing vessel. Chine breadth modification has been used for hull form variations. The objective function is the minimum value of wavemaking resistance. A parametric study was conducted to observe the effects of design parameters on the objective functions, and hull-form optimization was performed. In addition to the hull-form optimization, the effect of the stern flap was investigated in terms of both resistance and operational performances.

scholarly journals Mixed-Fidelity Design Optimization of Hull Form Using CFD and Potential Flow Solvers

2021 ◽  
Vol 9 (11) ◽  
pp. 1234
Author(s):  
Gregory J. Grigoropoulos ◽  
Christos Bakirtzoglou ◽  
George Papadakis ◽  
Dimitrios Ntouras
Keyword(s):  
Potential Flow ◽  
Stokes Equations ◽  
Computing Time ◽  
Navier Stokes ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Viscous Effects ◽  
Hull Form ◽  
Calm Water ◽  
Hull Forms

The present paper proposes a new mixed-fidelity method to optimize the shape of ships using genetic algorithms (GA) and potential flow codes to evaluate the hydrodynamics of variant hull forms, enhanced by a surrogate model based on an Artificial Neural Network (ANN) to account for viscous effects. The performance of the variant hull forms generated by the GA is evaluated for calm water resistance using potential flow methods which are quite fast when they run on modern computers. However, these methods do not take into account the viscous effects which are dominant in the stern region of the ship. Solvers of the Reynolds-Averaged Navier-Stokes Equations (RANS) should be used in this respect, which, however, are too time-consuming to be used for the evaluation of some hundreds of variants within the GA search. In this study, a RANS solver is used prior to the execution of the GA to train an ANN in modeling the effect of stern design geometrical parameters only. Potential flow results, accounting for the geometrical design parameters of the rest of the hull, are combined with the aforementioned trained meta-model for the final hull form evaluation. This work concentrates on the provision of a more reliable framework for the evaluation of hull form performance in calm water without a significant increase of the computing time.

Effects of Length on Frigate and Destroyer Performance and Cost

1988 ◽  
Vol 25 (04) ◽  
pp. 272-280
Author(s):  
J.L. Colwell
Keyword(s):  
Acquisition Cost ◽  
Propulsion System ◽  
Design Solution ◽  
Future Cost ◽  
Hull Form ◽  
Design Requirements ◽  
Hull Forms ◽  
Propulsion Power

The major effects of hull length on frigate and destroyer performance and cost are examined by comparing design candidates with common design requirements, but with different lengths. Three hull forms are considered; one is representative of contemporary NATO practice, one is relatively long, and one is relatively short. In some cases, the long hull form provides the least expensive design solution, as it can satisfy common design requirements with lower installed propulsion power. When comparing ships with the same propulsion system, the platform acquisition cost of the longer hull form is generally slightly higher than the contemporary and shorter hull forms (within 1 percent); however, in some cases both the long and contemporary hull forms have lower platform acquisition cost than the short one. Comparison of design candidates indicates that, even when the longer ship has higher platform acquisition cost, it has sufficient performance, arrangement and future cost advantages to justify the higher initial expense.

Application of the Global Optimization Method to the Preliminary Design of Tension Leg Platforms

2016 ◽  
Author(s):  
Jeong-Du Kim ◽  
Beom-Seon Jang
Keyword(s):  
Global Optimization ◽  
Limit State ◽  
Optimization Method ◽  
Total Weight ◽  
Design Parameters ◽  
Ultimate Limit State ◽  
Wave Loads ◽  
Hull Form ◽  
Optimization System ◽  
Design Requirements

The TLP requires a complicated and time-consuming design process. Principal dimension of hull form and tendons should be carefully determined with the consideration of many design requirements which dominantly affect the safety of the platform. In this paper, a global optimization system for both the hull-form and tendon system is developed. The maximum heave response and total weight of hull and tendons are formulated as an objective function with the several constraints related to the safety of platform. In order to find a technically and economically feasible design, a modelling and assessment processes are fully automated, which enables the algorithm can controls the modelling and analysis process while varying a set of design parameters until it figures out an optimum design. Major design requirements related to the safety of platform is assessed by ultimate limit state (ULS) and fatigue limit state (FLS) approach to ensure the accuracy of analysis. In the ULS approaches, every safety requirement is checked on the basis of the most unfavorable environments. FLS approach is conducted for all tendons since they suffer cyclic deformation for their service life, which results in collapse of mooring system with the relatively small wave loads. In the optimization module, a better set of design parameters is investigated by using a simulated annealing (SA) algorithm. Throughout the optimization system, both the heave responses and total weight of hull and tendons are improved while satisfying the all constraints related to the design requirements.

scholarly journals Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

2021 ◽  
Vol 13 (5) ◽  
pp. 2756
Author(s):  
Federica Vitale ◽  
Maurizio Nicolella
Keyword(s):  
Building Materials ◽  
Thermal Analyses ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Research Trends ◽  
Mix Design ◽  
Recycled Aggregates ◽  
Design Parameters ◽  
Natural Aggregates ◽  
By Products

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

scholarly journals ECCLESIASTIC TYPIKON FROM THE SCIENTIFIC LIBRARY OF KYIV UNIVERSITY: ATTRIBUTION OF MANUSCRIPT

2018 ◽  
pp. 24-29
Author(s):  
S. Voloshchenko
Keyword(s):  
Key Words ◽  
Construction Materials ◽  
The State ◽  
Slavonic Language ◽  
National University ◽  
History Of ◽  
Rare Books ◽  
And Migration

The principles of scientific attribution of liturgical cyrillic manuscripts, which has been worked out by author, are examined. The thorough study of Jerusalem Ecclesiastic Typikon from the rare books and manuscripts department’s collection of Maksymovych Scientific Library of Taras Shevchenko National University of Kyiv is conducted. The stages of manuscript attribution are analyzed, including the date identification and localization of its origins and use. The type and the title of the codex have been identificated by the analysis of book’s texts. The linguistic variant of Church Slavonic language, used for re-writing the copy, is revealed, which has helped to localize the place of creation. Detailed watermark analysis of paper, which the copy had been made of, has allowed to estimate date range of its production. The problematic ascertainment of the date of creation has been also supported by the analysis of the textual sources, studying of palaeographic peculiarities of cyrillic script book, the inner book’s decorative features. The problem of binding production date, its construction, materials and design, is formulated. The state of preservation of manuscript is analysed, which led the author to understanding the extent of book’s relevance for its readers. The history of manuscript restoration and its stages have been studied. The places of use and migration of the copy are revealed on the basis of provenance examination up till its arrival to Maksymovych Scientific Library’s rare books collection. Key words: Jerusalem Ecclesiastic Typikon, manuscript, Cyrillic manuscript, attribution, codicology, Maksymovych Scientific Library of Taras Shevchenko National University of Kyiv.

Design & Analysis of Steam Drum Based on ASME Boiler and Pressure Vessel Code, Section VIII Div.2 & Div.3

2016 ◽  
Vol 852 ◽  
pp. 511-517
Author(s):  
Vishal Payghan ◽  
Dattatray N. Jadhav ◽  
Girish Y. Savant ◽  
Sagar Bharadwaj
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pressure Vessel ◽  
Design Parameters ◽  
Plastic Collapse ◽  
Finite Element Stress Analysis ◽  
Process Plant ◽  
Section Viii ◽  
Design Requirements ◽  
Steam Drum

Process plant industries have equipment working on high pressure and high temperature environments. The ASME Boiler and Pressure Vessel Code, Section VIII provides rules for construction of the pressure vessel. The purpose of this paper is to have comparative study for design and analysis of steam drum using ASME Section VIII Div. 2 and Div. 3. Steam drum is a part of boiler system and works at high pressure and high temperature. Normally, Steam drum design is based on ASME Section VIII Div. 2, Part 4, design by rule and Part 5, design by analysis; which has been carried out in the present study. In this paper, design of the same equipment is studied using Part KD, Design requirements of ASME Section VIII Div. 3 with similar design parameters. Finite Element Stress Analysis of both design has been done as per code requirements to check the plastic collapse. In this study, it is observed that there is reduction in the required thickness for design based on Div. 3. Finally, the reduced required thickness leads to considerable weight reduction of the equipment and thus increased competitiveness.

Geometrical Characteristics of Fishing Boats Series of ITU

2007 ◽  
Vol 44 (02) ◽  
pp. 125-137
Author(s):  
Muhsin Aydin ◽  
Aydin Salci
Keyword(s):  
Computer Program ◽  
The Body ◽  
Hull Form ◽  
The Third ◽  
Geometrical Characteristics ◽  
Fishing Boat ◽  
Technical University ◽  
Hull Forms

In the present paper, first 13 hull forms of fishing boats with different block coefficients were generated. Later, 26 hull forms of fishing boats with two different ratios of length to beam were generated by utilizing previous hull forms of fishing boats mentioned. In total, 39 fishing boats were generated. This series is called "Fishing Boats Series of ITU" (Istanbul Technical University). In this Series, the forms of the body stations and beams of the boats are the same for equal block coefficient and different lengths. The ratio of the beam of any station at any waterline to the beam of boat, Bz/B varies with respect to block coefficient, CB. These variations have been represented with the third-degree polynomials. Thus, a hull form of the fishing boat in the desired length and block coefficient can be obtained by using these polynomials. For this purpose, a computer program called "Turetme" was developed. Finally, by using this program, three hull forms of fishing boats were obtained and presented here.

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