Modelling and Analysis of Turning Motion of a Subsurface Mapping AUV with Split-Hull Design

2021 ◽  
Author(s):  
Vishakh S. Kumar ◽  
Prabhu Rajagopal
Keyword(s):  
Hull Design ◽  
Turning Motion ◽  
Subsurface Mapping

Analysis on nonlinear turning motion of multi-spherical soft robots

2016 ◽  
Vol 88 (2) ◽  
pp. 883-892 ◽  
Author(s):  
Yanqiong Fei ◽  
Wu Pang
Keyword(s):  
Soft Robots ◽  
Turning Motion

Quasi-developable -spline surfaces in ship hull design

2007 ◽  
Vol 39 (10) ◽  
pp. 853-862 ◽  
Author(s):  
F. Pérez ◽  
J.A. Suárez
Keyword(s):  
Ship Hull ◽  
Spline Surfaces ◽  
Hull Design

Mathematical Hull Design for Sailing Yachts

1981 ◽  
Author(s):  
John S. Letcher
Keyword(s):  
Historical Perspective ◽  
Analytic Form ◽  
Surface Shape ◽  
Analytic Geometry ◽  
Representation System ◽  
Construction Methods ◽  
Small Craft ◽  
Hull Design ◽  
Basic Concepts ◽  
Mathematical Design

Mathematical representations of hull surface shape have largely supplanted graphical fairing and lofting of lines in the shipbuilding and aircraft industries, but have had little application so far to small craft. Past methods of hull design are surveyed to put mathematical design into historical perspective and point up its many advantages. The basic concepts of analytic geometry of surfaces needed for yacht hull design are briefly introduced with references. Several special aspects of the geometry of yacht hulls, arising from considerations of aesthetics, hydrodynamics, and construction methods are discussed and cast into analytic form for inclusion in a hull design scheme. The paper explains in detail a particular representation system called FAIRLINE/1, simple enough to fit into the program and memory limitations of a TI-59 calculator, yet extremely versatile. A program listing and several example hull designs created with this program are presented.

A Novel Submarine Pressure Hull Design

1987 ◽  
Vol 31 (03) ◽  
pp. 186-188
Author(s):  
C. T. F. Ross
Keyword(s):  
Alternative Design ◽  
Hull Design

The paper presents an alternative design for a submarine pressure hull, which has no ring-stiffeners, but where shell instability and general instability are resisted by making the pressure hull of a swedged-shaped form. Calculations on two different-sized pressure hulls appear to indicate that the swedged-shaped hulls are more structurally efficient than their ring-stiffened equivalents.

Experimental Study on the Stability Performance and Turning Motion of Multi-Connection VAWT

2021 ◽  
Author(s):  
Saika Iwamatsu ◽  
Yasunori Nihei ◽  
Kazuhiro Iijima ◽  
Tomoki Ikoma ◽  
Tomoki Komori
Keyword(s):  
Scaling Law ◽  
Type A ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Water Tank ◽  
Type B ◽  
Floating Bodies ◽  
Stability Performance ◽  
Turning Motion ◽  
The Stability

Abstract In this study, a series of dedicated water tank tests were conducted in wind and waves to investigate the stability performance and turning motion of Floating Offshore Wind Turbine (FOWT) equipped with two vertical axis wind turbines (VAWT). The FOWT targeted in this study is called Multi-connection VAWT, which is a new type of FOWT moored by Single-Point-Mooring (SPM) system. We designed and manufactured two types of semi-submersible floating bodies. One is a type in which VAWTs are mounted in two places of a right-angled isosceles triangle (Type-A) on a single floater, and the other is two independent units equipped with VAWTs on two separate floaters centered on a moored body. This is a type in which two semi-submersible floating bodies are lined up in a straight line (Type-B). The experimental conditions were determined by scaling down to 1/100 using Froude’s scaling law based on a wind thrust load of 320 kN (rated wind speed of 12 m/s) assuming an actual machine. In the free yawing test in waves, Type-A turned downwards, while Type-B was barely affected by the waves. Furthermore, in the free yawing test in wind, both Type-A and Type-B turned leeward and stabilized at a final point where the wind load was balanced.

‘Scows, and barges, or other vessels of box model’: Comparative capital investment in the sailing scows of the Great Lakes of North America and in New Zealand

2018 ◽  
Vol 30 (1) ◽  
pp. 89-105
Author(s):  
Jay C. Martin
Keyword(s):  
New Zealand ◽  
North America ◽  
Great Lakes ◽  
Capital Investment ◽  
Open Water ◽  
Long Distance ◽  
American Frontier ◽  
International Context ◽  
The North ◽  
Hull Design

Boxy and with ‘unseaworthy form’, the sailing scow was not the most aesthetically pleasing of watercraft. Yet the durable hull design based upon European predecessors found a new home in North America where it proliferated on the Atlantic, Gulf, Pacific and Great Lakes coasts because of its practicality for largely unimproved waterways. Scows were widely used on the Great Lakes in the nineteenth century, moving beyond shallow waters and gaining a reputation for reliability in long-distance trade. Late in the century, the technology arrived in New Zealand, where it prospered in a niche market that combined open water voyages and shallow river, port, or beach loading and unloading. The Great Lakes scows presented an alternative for entry into ship ownership on the North American frontier. The development of the New Zealand scow confirmed these findings comparatively in an international context during the late nineteenth and early twentieth centuries.

Feasibility of Using Stress Joint in an Existing Flexible Joint Receptacle for a Deepwater SCR

2009 ◽  
Author(s):  
Basim Mekha ◽  
Alok Kumar ◽  
Mike Stark ◽  
Paul Barnett
Keyword(s):  
Bending Moment ◽  
Flexible Joints ◽  
Floating Structure ◽  
Element Analysis ◽  
Flexible Joint ◽  
Floating Structures ◽  
Operational Problem ◽  
Hull Structure ◽  
Hull Design ◽  
Titanium Material

In recent years, most fluid produced or exported has been transported using steel catenary risers (SCRs) attached to deepwater floating structures. The SCRs are terminated at the floating structures using Top Termination Units (TTUs) such as flexible joints or tapered stress joints. The flexible joints are usually designed to allow the riser to rotate with the floating structure motion and reduce the amount of moments transferred to the hull structure. The flexible joints depend on the flexibility and compressibility of the elastomer layers to allow for the rotation of the SCR. The stress joints, alternatively, provide fixed support at the hull and thus larger bending moment that has to be accounted for in the hull design. The stress joints can be made of steel or titanium material. The SCR TTU’s receptacle, which will be welded to the hull porch and contains the TTU basket, has to be designed to meet the force and reaction requirements associated with the selected TTU type. However, in some cases which could be due to failure of the TTU to meet the expected life or the operational requirements, the operators may have to replace the damaged TTU with another one or with a different TTU type. A few examples are available in the Gulf of Mexico. Recently the Flexible Joint TTU of the Independent Hub 20-inch export SCR had an operational problem. During the course of investigating the related issues and studying possible solutions, one option considered was the feasibility of replacing the Flexible Joint (FJ) with Titanium Tapered Stress Joint (TSJ). This paper highlights the issues that have to be considered in the design of the FJ existing receptacle to accommodate the force reactions of a Titanium TSJ. These issues are addressed and the results of the detailed finite element analysis performed are provided. The analysis conclusions, which are related to the feasibility of the existing receptacle to receive the loads imposed by TSJ and the modifications required to achieve this, are presented.

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