scholarly journals Experimental and Numerical Investigation on the Transport Characteristics of Particle-Fluid Mixture in Y-Shaped Elbow

2020 ◽  
Vol 8 (9) ◽  
pp. 675
Author(s):  
Qiong Hu ◽  
Li Zou ◽  
Tong Lv ◽  
Yingjie Guan ◽  
Tiezhi Sun
Keyword(s):  
Deep Sea ◽  
Pipe Wall ◽  
Large Diameter ◽  
Surface Mining ◽  
Sea Surface ◽  
Mining System ◽  
Fluid Mixture ◽  
High Frequencies ◽  
Motion Characteristics ◽  
Actual Particle

The Y-shaped elbow is used as a connecting pipe between the buffer and the lift pipe in the deep-sea mining system. After being mixed with seawater in the Y-shaped elbow, nodule particles are lifted to the sea surface mining ship via the lift pump. In this paper, we employ a computational fluid dynamics and discrete element coupled method (CFD-DEM) to study the characteristics of particle transport in the Y-shaped elbow. Considering a large diameter of the particles, we discuss the behavior of particles and fluid under different conveying velocities. In addition, the simulation was verified based on the experiment. The results show that the simulation agrees well with the experiment. On this basis, the distribution and motion characteristics of the particles in the Y-shaped elbow were obtained. The interaction between fluid and particles is also discussed. These findings suggest that the particles can be successfully transported when the pump runs at medium to high frequencies. The particles are basically moving along the pipe wall and slower than the fluid flow. Moreover, it was found that the particle motions are more complex with the increasing of conveying velocities, and it is closely related to the secondary flow of fluid. Some suggestions on the actual particle transportation can be put forward based on the research in this paper.

Pacific Ocean deep sea surface height fluctuation

2007 ◽  
Author(s):  
Todd Holden ◽  
P. Marchese ◽  
G. Tremberger, Jr. ◽  
D. Cotten ◽  
T. D. Cheung ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Deep Sea ◽  
Sea Surface Height ◽  
Sea Surface

Motion Characteristics of a Spar-Buoy With Ring-Fin Motion Stabilizer in Deep Sea

2021 ◽  
Author(s):  
Yusuke Ymamoto ◽  
Toru Katayama ◽  
Taishi Morimoto ◽  
Masahiro Goto
Keyword(s):  
Deep Sea ◽  
Motion Characteristics

Concept Design of Mining System of Seafloor Hydrothermal Deposit

2010 ◽  
Author(s):  
Shinichi Takagawa
Keyword(s):  
Economic Evaluation ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Environmental Effect ◽  
State Of The Art ◽  
Concept Design ◽  
Hydrothermal Deposit ◽  
Mining System ◽  
Positive Balance ◽  
Rough Sea

Japan Deep Sea Technology Association had carried out concept design of the mining system for seafloor hydro-thermal deposit from 2008 through 2009. Through this concept design, the economic evaluation of the system with parameter of annual production of the ore was discussed, and it was clarified that more than 500 thousand tons annually would enable us to get positive balance. The environmental effect by mining was also discussed and was concluded that the active hydrothermal vents are not the targets of mining, instead, the dead vents are the targets. Then, the technological feasibility of each subsystem was discussed which constitutes the mining system, from the digger to the surface transporter. Finally, it was concluded that the mining system for hydrothermal deposits is feasible using the state-of-the-art technology even in rough sea around Japan.

scholarly journals Relation between orbital velocities, pressure and surface elevation in non-linear nearshore water waves

2021 ◽  
Author(s):  
Kévin Martins ◽  
Philippe Bonneton ◽  
David Lannes ◽  
Hervé Michallet
Keyword(s):  
Free Surface ◽  
Surface Energy ◽  
Water Waves ◽  
Energy Levels ◽  
Sea Surface ◽  
Surface Elevation ◽  
Linear Wave ◽  
Free Surface Elevation ◽  
High Frequencies ◽  
Non Linear

AbstractThe inability of the linear wave dispersion relation to characterize the dispersive properties of non-linear shoaling and breaking waves in the nearshore has long been recognised. Yet, it remains widely used with linear wave theory to convert between sub-surface pressure, wave orbital velocities and the free surface elevation associated with non-linear nearshore waves. Here, we present a non-linear fully dispersive method for reconstructing the free surface elevation from sub-surface hydrodynamic measurements. This reconstruction requires knowledge of the dispersive properties of the wave field through the dominant wavenumbers magnitude κ, representative in an energy-averaged sense of a mixed sea-state composed of both free and forced components. The present approach is effective starting from intermediate water depths - where non-linear interactions between triads intensify - up to the surf zone, where most wave components are forced and travel approximately at the speed of non-dispersive shallow-water waves. In laboratory conditions, where measurements of κ are available, the non-linear fully dispersive method successfully reconstructs sea-surface energy levels at high frequencies in diverse non-linear and dispersive conditions. In the field, we investigate the potential of a reconstruction that uses a Boussinesq approximation of κ, since such measurements are generally lacking. Overall, the proposed approach offers great potential for collecting more accurate measurements under storm conditions, both in terms of sea-surface energy levels at high frequencies and wave-by-wave statistics (e.g. wave extrema). Through its control on the efficiency of non-linear energy transfers between triads, the spectral bandwidth is shown to greatly influence non-linear effects in the transfer functions between sub-surface hydrodynamics and the sea-surface elevation.

scholarly journals Graphic correlation of deep sea and shallow marine deposits from the Central American Isthmus region: implications for Late Neogene paleoclimatology

1992 ◽  
Vol 6 ◽  
pp. 88-88
Author(s):  
Harry J. Dowsett
Keyword(s):  
Costa Rica ◽  
High Resolution ◽  
Ocean Circulation ◽  
Deep Sea ◽  
Sea Surface ◽  
Central American ◽  
Major Barrier ◽  
Late Neogene ◽  
The Caribbean ◽  
Central American Isthmus

The stratigraphic record in Panama and Costa Rica preserves the biologic and climatic changes associated with the formation of a major barrier to marine migration and ocean circulation. Creating a high resolution temporal framework within which stratigraphic sections found on the Isthmus can be interpreted is fundamental to our understanding the history and importance of these units.The Isthmus contains rich marine macro- and microfaunas and floras on both the Pacific and Atlantic margins. Planktic foraminifers and calcareous nannofossils are common and often well preserved. Preliminary analysis of these fossils reveals a rich sedimentary record spanning the Late Miocene to Pleistocene. Multivariate statistical analyses of these assemblages provide environmental estimates. Unfortunately, traditional methods of biostratigraphy are limited in their ability to create a high resolution temporal framework for the region. For example, a majority of deposits analyzed can be placed in planktic foraminiferal zone N19 (early Pliocene). In order to answer paleobiologic and paleoclimatic questions one requires more precise correlations between sections and some indication of duration of sedimentation represented by various sections.In an attempt to overcome the shortcomings of traditional biostratigraphic methods, the Graphic Correlation method has been applied to selected sequences on the Central American Isthmus. Graphic correlation (GC) is a procedure by which two sequences can be compared and correlated using a wide variety of stratigraphic information simultaneously. A GC model of late Neogene planktic foraminifer, calcareous nannofossil, and paleomagnetic reversal events has been produced through compositing of more than 26 deep sea cores and ocean margin sequences. Following routine GC procedures the positions of all fossil first and last occurrences from a number of sections on the Caribbean and Pacific sides of the Central American Isthmus (Panama and Costa Rica) have been recorded. These sections have been correlated to the GC model and hence, to each other, providing a temporal framework for the Isthmus units.Selected sections were then correlated to other sequences such as near-by deep sea cores which have been analyzed for sea surface temperature and salinity to gain a better understanding of the overall paleoceanographic development of the region between 5 and 2 Ma. For example, correlation of units on the Caribbean side of the Isthmus with DSDP Site 502 indicates little to no change in sea surface temperatures during the entire time the Isthmus was reaching closure. Mid-to-high latitude sites exhibit amplification of warming with increasing latitude. The shoaling Isthmus, while having negligible effects on tropical marine temperatures, was responsible for increased meridional heat transport which resulted in a North Atlantic warming about 3 Ma. A general model for paleoceanographic changes during the time of closure will be discussed.

An Integral Design Approach for Deep Sea Mining Systems Using Dredging Technology

2010 ◽  
Author(s):  
P. M. Vercruijsse ◽  
R. Lotman
Keyword(s):  
Transport System ◽  
Deep Sea ◽  
Mining Operation ◽  
Integral Solution ◽  
Mechanical Interaction ◽  
Pumping Power ◽  
Mining System ◽  
Mining Tool ◽  
Transport Flow ◽  
Slurry Transport

Experience in the area of wet mining and the dredging industry learns that the excavation system cannot be seen separate from the slurry transportation system. These two key systems in a deep sea mining operation interrelate to such extend that they must be developed towards an integral solution. The nominal production, peak production and variability of these figures must match for all sub-systems in the overall mining system to optimize for mining efficiency; we call this the ‘game of capacities’. Also the configuration of the excavation and transport system has great consequences. For instance an important question is whether to place the first pump and its drive of the slurry transport system on the seafloor mining tool or in the riser system. The choices made impact amongst others on; the mining tool’s reach (and thus efficiency), the seafloor mining tool’s propulsion system and its geo-mechanical interaction, the slurry transport flow and pumping power requirements. This paper will discuss the several dependencies of the (producing) subsystems and important choices for configuration and their consequences regarding technology, capex, opex, reliability and maintainability.

Pump-lockage ore transportation system for deep sea flexible mining system

2008 ◽  
Vol 15 (4) ◽  
pp. 540-544 ◽  
Author(s):  
Hai-liang Xu ◽  
Ping-wei Yin ◽  
Shao-jun Xu ◽  
Fang-qiong Yang
Keyword(s):  
Deep Sea ◽  
Transportation System ◽  
Mining System
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