Concept Design of a New Non-Ship-Shaped FPSO

2012 ◽  
Vol 170-173 ◽  
pp. 2222-2227 ◽  
Author(s):  
Tian Ying Wang ◽  
Jian Zhang ◽  
Jin Kun Liu

In order to give full play to the advantages of FPSOs in the development of offshore oilfields, a new non-ship-shaped FPSO concept named IQFP is put forward through intensive study on various factors affecting the performance of FPSOs. Then, the optimized IQFP general design of a project case is presented based on the IQFP concept. The intact stability and damage stability of the IQFP are calculated and checked according to IMO rules. The hydrodynamic performance in frequency domain is simulated using the three-dimensional potential flow theory and compared with that of a ship-shaped FPSO with similar tonnage. The results indicate that the IQFP has a large stability margin and more excellent hydrodynamic performance than the ship-shaped FPSO. Through the research of this paper, the excellent characteristic of the new FPSO concept IQFP is verified and the basis and foundation are provided for the further studies.

2019 ◽  
Vol 7 (12) ◽  
pp. 450 ◽  
Author(s):  
Francesco Mauro ◽  
Luca Braidotti ◽  
Giorgio Trincas

To face the design of a new ship concept, the evaluation of multiple feasible solutions concerning several aspects of naval architecture and marine engineering is necessary. Compressed natural gas technologies are in continuous development; therefore, there are no available databases for existing ships to use as a basis for the design process of a new unit. In this sense, the adoption of a modern multi-attribute decision-based method can help the designer for the study of a completely new ship prototype. A database of compressed natural gas ships was generated starting from a baseline hull, varying six hull-form parameters by means of the design of experiment technique. Between the attributes involved in the concept design process, stability is for sure one of the most relevant topics, both for intact and damaged cases. This work describes two approaches to identify the compliance of a ship with the intact stability regulations based on the ship main geometrical quantities. Moreover, a metamodel based on the maximum floodable length concept (damage stability) allows determining the main internal subdivision of the ship. The metamodel outcomes were compared with results from direct calculations on a ship external to the database, highlighting the adequate accuracy given by the developed methods.


2015 ◽  
Author(s):  
Rodrigo Perez ◽  
Verónica Alonso

Many tools handle with the calculation of compartment definition, hydrostatics, intact and damage stability and power prediction, but these calculations are separated from the rest of ship CAD/CAM tools. Ship designers need to work closely with the shipyards, in a complex and distributed environment making necessary to have suitable tools at early design stages to ensure profitable projects. Naval architecture is handled in FORAN with a revolutionary approach, where integration and advanced features are the relevant characteristics in a single and complete set of applications that are used in conjunction to other disciplines, from concept design to operation. This new approach groups the former modules for naval architecture available in FORAN from many years, is intuitive and user-friendly. The information is stored in a database instead of a wide set of files. As regards this feature, there are two different alternatives depending on the scope of the project. If the ship designer wants to calculate only naval architecture calculations, the solutions is based on a SQLITE database suitable for a standalone application. This approach benefits a ship design office, in the study of different design alternatives very quickly but having a complete control of them. The other option is integrating the Naval Architecture with the rest of FORAN design disciplines, in a single database based in Oracle. In this case, the great benefit comes from the single truth of data from concept design to operation, which ensures dramatically the reduction of errors and re-work. After the definition of compartments in 3D, by using a very fast application, the module guides the user through the naval architecture calculations with a tree of elements very intuitive, with powerful key algorithms and with a solid representation of spaces. The definition of the necessary entities to make any kind of calculation is very fast. For the intact stability a set of standard stability criteria is provided. It is based in a quick definition of loading conditions, initial situations, flooding conditions and compartment subdivisions. And for the evaluation of the damage stability a set of standard stability criteria are also provided, following deterministic and probabilistic approaches. With these tools any naval architect is able to make very fast all the necessary studies to assure the stability regulations are complied with.


2020 ◽  
Vol 8 (3) ◽  
pp. 176 ◽  
Author(s):  
Jeong-Seok Kim ◽  
Bo Woo Nam ◽  
Kyong-Hwan Kim ◽  
Sewan Park ◽  
Seung Ho Shin ◽  
...  

In this study, a time-domain numerical method based on three-dimensional potential flow was developed to analyze the hydrodynamic characteristics of an inclined oscillating-water-column (OWC) wave energy converter (WEC). A finite element method was applied to solve the potential flow around and inside the OWC chamber. A turbine–chamber interaction was considered to take into account the pressure drop inside the OWC chamber, which is a nonlinear function of airflow speed via turbine operation. The instantaneous pressure drop was updated on the free-surface boundary condition inside the chamber in the time-domain to account for the coupling effect between the turbine and the chamber. The present numerical method was verified by comparing it with the model test results. The hydrodynamic characteristics of an inclined OWC chamber in terms of potential flow, such as the water column motion and the three-dimensional flow distribution around the chamber, were investigated. In terms of hydrodynamic performance, the energy conversion efficiency of the chamber showed a nonlinear response characteristic dependent on the incident wave height. In addition, numerical calculations were carried out to clarify the relationship between the main geometric parameters and the hydrodynamic response of the inclined OWC chamber.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Konrad Rolle ◽  
Dmytro Yaremkevich ◽  
Alexey V. Scherbakov ◽  
Manfred Bayer ◽  
George Fytas

AbstractHypersonic phononic bandgap structures confine acoustic vibrations whose wavelength is commensurate with that of light, and have been studied using either time- or frequency-domain optical spectroscopy. Pulsed pump-probe lasers are the preferred instruments for characterizing periodic multilayer stacks from common vacuum deposition techniques, but the detection mechanism requires the injected sound wave to maintain coherence during propagation. Beyond acoustic Bragg mirrors, frequency-domain studies using a tandem Fabry–Perot interferometer (TFPI) find dispersions of two- and three-dimensional phononic crystals (PnCs) even for highly disordered samples, but with the caveat that PnCs must be transparent. Here, we demonstrate a hybrid technique for overcoming the limitations that time- and frequency-domain approaches exhibit separately. Accordingly, we inject coherent phonons into a non-transparent PnC using a pulsed laser and acquire the acoustic transmission spectrum on a TFPI, where pumped appear alongside spontaneously excited (i.e. incoherent) phonons. Choosing a metallic Bragg mirror for illustration, we determine the bandgap and compare with conventional time-domain spectroscopy, finding resolution of the hybrid approach to match that of a state-of-the-art asynchronous optical sampling setup. Thus, the hybrid pump–probe technique retains key performance features of the established one and going forward will likely be preferred for disordered samples.


2008 ◽  
Vol 45 (03) ◽  
pp. 147-156
Author(s):  
Marcelo A. S. Neves ◽  
Vadim Belenky

The paper gives a brief review of the papers presented at the Ninth International Conference on Stability of Ships and Ocean Vehicles that was held on September 25 to 29, 2006 in Rio de Janeiro, Brazil. The review covers the following stability-related subjects: stability regulations, intact stability, wind and waves, damage stability, stability in operation, stability of high-speed craft, and offshore vehicles.


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