Risk-based Simulation Models for the Construction of the Mobile Offshore Base

2000 ◽  
Vol 16 (04) ◽  
pp. 241-252
Author(s):  
William J. Bender ◽  
Andrew N. Blair ◽  
Bilal M. Ayyub
Keyword(s):  
Simulation Models ◽  
Construction Cost ◽  
Simulation Software ◽  
Naval Research ◽  
Floating Structure ◽  
Feasibility Assessment ◽  
Office Of Naval Research ◽  
The Us ◽  
Resource Requirements ◽  
Mobile Offshore Base

Several very large ocean structures have been proposed as part of the Office of Naval Research feasibility study of a Mobile Offshore Base (MOB). The MOB platform nominally is about 1500 m (l mile) by 129 m (400 ft), which is unprecedented in size and operations compared to any floating structure to date. The objective of this study was to provide a risk-informed construction feasibility assessment for five proposed MOB concepts and quantify their construction cost and schedule. The risks associated with the concepts' cost and schedule were established by comparing resource requirements to build a MOB with the US industrial capacity. These risks were then modeled and simulated using commercial simulation software to provide cost and schedule estimates that accounted for uncertainty and risks. The scope of this study was limited to the construction of the hull.

CHARACTERISTICS OF MOLTEN SALTS AND RECOMMENDATIONS FOR USE IN SOLAR POWER STATIONS

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Samaan G. Ladkany ◽  
William G. Culbreth ◽  
Nathan Loyd
Keyword(s):  
Molten Salt ◽  
Molten Salts ◽  
Solar Power ◽  
Weather Conditions ◽  
Thermal Capacity ◽  
Naval Research ◽  
Power Stations ◽  
Office Of Naval Research ◽  
The Us ◽  
Efficient Type

Molten salts (MS) in the 580°C range could be used to store excess energy from solar power stations and possibly from nuclear or coal. The energy can be stored up to a week in large containers at elevated temperature to generate eight hours of electricity to be used at night or during peak demand hours. This helps to reduce the fluctuation experienced at thermal solar power stations due to weather conditions. Our research supported by Office of Naval Research (ONR), presents a survey of salts to be used in molten salt technology. The physical characteristics of these salts such as density, melting temperature, viscosity, electric conductivity, surface tension, thermal capacity and cost are discussed. Cost is extremely important given the large volumes of salt required for energy storage at a commercial power station. Formulas are presented showing the amount of salt needed per required megawatts of stored energy depending on the type of salt. The estimated cost and the size of tanks required and the operating temperatures are presented. Recommendations are made regarding the most efficient type of molten salt to use. Commercial thermal solar power stations have been constructed in the US and overseas mainly in Spain for which molten salt is being considered. A field of flat mirrors together with collection towers are used in some designs and parabolic troughs used in others.

scholarly journals Little Big El-Mo

2001 ◽  
Vol 123 (10) ◽  
pp. 52-55 ◽  
Author(s):  
Paul Sharke
Keyword(s):  
High Temperature ◽  
Assembly Line ◽  
Naval Research ◽  
New Techniques ◽  
Ship Propulsion ◽  
High Temperature Superconducting ◽  
Superconducting Motor ◽  
Office Of Naval Research ◽  
The Us ◽  
The Many

This article reviews the arrival of commercial high-temperature superconducting (HTS) motors in the market. American Superconductor is concentrating its motor efforts on ship propulsion. The company has a contract with the US Navy’s Office of Naval Research to design and develop propulsion motors up to 33,500 hp. The big advantage of a superconducting motor aboard a ship is its small size, which frees up valuable square footage in the hull for the many other components needed in battle. Because superconducting motors will be about half the weight of their conventional counterparts, the efficiencies an assembly line brings to manufacturing suddenly open for many of them. Lighter, smaller designs also will translate to time saved in testing. Many of the technologies used in the 200-hp machine transferred to the 1000-hp unit, and many new techniques developed as well.

scholarly journals Excessive Acceleration Criterion: Application to Naval Ships

2019 ◽  
Vol 7 (12) ◽  
pp. 431 ◽  
Author(s):  
Guido Boccadamo ◽  
Gennaro Rosano
Keyword(s):  
Failure Modes ◽  
Vertical Direction ◽  
Naval Research ◽  
Stability Criteria ◽  
Office Of Naval Research ◽  
Intact Stability ◽  
The Us ◽  
Ship Roll ◽  
Hull Forms ◽  
Level 2

In this paper, the application of the excessive acceleration (EA) criterion, one of five intact stability failure modes, within the second generation intact stability criteria (SGISC) framework, is shown for a set of naval vessels. First and second level vulnerability assessment of the criterion is applied to parent hulls D1 and D5 of D-Systematic Series, the US Office of Naval Research (ONR) Topside Series model, and the European multi-purpose frigate FREMM. All of which are semi-displacement, transom stern, and round bilge hull forms. Relatively low ship roll periods and great variations of hull geometry in vertical direction make this kind of ship potentially vulnerable to the EA phenomenon. Five displacements are considered for each vessel, and the minimum value of the KG height, which satisfies the Level 2 assessment, is computed for each of them. The curve of the minimum allowable KG is compared with the curve of the maximum KG complying with intact stability criteria specified in RINA (Registro Italiano Navale), classification rules for naval ships.

Sign in / Sign up

Export Citation Format

Share Document