Review on the design and mechanics of bonded marine hoses for Catenary Anchor Leg Mooring (CALM) buoys

2022

JMSE

Self Cite

The application of marine bonded hoses has increased in recent times, due to the need for more flexible conduits and flexible applications in the offshore industry. These marine structures include Catenary Anchor Leg Moorings (CALM) buoys and ocean monitoring buoys. Their attachments include floating hoses, submarine hoses and submarine cables. However, the structural performance challenges of a CALM buoy system from its hydrodynamics water waves and other global loadings, have led to the need for this investigation. In this study, a detailed presentation on the motion characterisation of the CALM buoy hose system is presented. The CALM buoy is a structure with six degrees of freedom (6DoF). A well-detailed experimental presentation on the CALM buoy hose model conducted in Lancaster University Wave Tank is presented using three novel techniques, which are: a digital image captured using Imetrum systems, using an Akaso 4K underwater camera, using wave gauges arranged in a unique pattern and using underwater Bluetooth sensors. The buoy model was also found to respond uniquely for each motion investigated under water waves. The results showed that the higher the profile, the higher the response of the buoy. Thus, this study confirms the existence of flow patterns of the CALM buoy while floating on the water body.

Section: Methodsmentioning

confidence: 99%

“…The stability of the buoy will also determine the lifespan of the marine buoys and mooring lines. However, these marine bonded hoses are challenged with different structural issues, despite being very efficient in fluid delivery [27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Motion Characterisation of CALM Buoy Hose System under Water Waves

Amaechi

2022

JMSE

Self Cite

“…The marine environment is complex and changeable. The motion of floating offshore platforms, buoys, and ships is affected by waves, currents, wind, and variations in water depth owing to the tide [61][62][63][64]. For example, in certain seas, such as Nigeria's Bonga Field in offshore West Africa, near-surface currents are usually powerful and vary with time and location [63].…”

Section: Image Characteristics With a Sea-sky Backgroundmentioning

confidence: 99%

“…The motion of floating offshore platforms, buoys, and ships is affected by waves, currents, wind, and variations in water depth owing to the tide [61][62][63][64]. For example, in certain seas, such as Nigeria's Bonga Field in offshore West Africa, near-surface currents are usually powerful and vary with time and location [63]. But for ship detection in marine environments, most researchers pay more attention to the impact of ship appearance changes on identification.…”

Section: Image Characteristics With a Sea-sky Backgroundmentioning

confidence: 99%

A Review of Methods for Ship Detection with Electro-Optical Images in Marine Environments

Fan

et al. 2021

JMSE

The ocean connects all continents and is an important space for human activities. Ship detection with electro-optical images has shown great potential due to the abundant imaging spectrum and, hence, strongly supports human activities in the ocean. A suitable imaging spectrum can obtain effective images in complex marine environments, which is the premise of ship detection. This paper provides an overview of ship detection methods with electro-optical images in marine environments. Ship detection methods with sea–sky backgrounds include traditional and deep learning methods. Traditional ship detection methods comprise the following steps: preprocessing, sea–sky line (SSL) detection, region of interest (ROI) extraction, and identification. The use of deep learning is promising in ship detection; however, it requires a large amount of labeled data to build a robust model, and its targeted optimization for ship detection in marine environments is not sufficient.

“…Recently, applications of bonded flexible risers, unbonded flexible risers, composite risers, and marine hoses have increased in the marine industry [1][2][3][4][5][6][7][8][9]. This is due to the need for more flexible offshore platforms and lighter sustainable materials [10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Investigation on Hydrodynamic Characteristics, Wave–Current Interaction and Sensitivity Analysis of Submarine Hoses Attached to a CALM Buoy

Amaechi

2022

JMSE

Self Cite

There is an increase in the utilization of the floating offshore structure (FOS) called Catenary Anchor Leg Mooring (CALM) buoys and the attached marine hoses due to the increasing demand for oil and gas products. These hoses are flexible and easier to use but have a short service life of about 25 years. They are adaptable in ocean locations of shallow, intermediate and deep waters. In this research, a numerical model was developed using a coupling method modeled by utilizing ANSYS AQWA and Orcaflex (Orcina Ltd., Ulverston, UK) dynamic models of the CALM buoy hoses. Two cases were comparatively studied: Lazy-S and Chinese-lantern configurations, under ocean waves and current. Comparisons were also made between coupled and uncoupled models. This research presents the hydrodynamic characteristics with a sensitivity analysis on the influence of waves, current attack angle, soil gradient, soil stiffness and environmental conditions that influence the performance of marine hoses. The study comparatively looked at the configurations from dynamic amplification factors (DAF) on marine hoses. The results show that marine hoses can be easily configured to suit the designer’s need, seabed soil type, seabed topography and the profiles that are useful for manufacturers. The sensitivity analysis also shows the effect of hose parameters on its hydrodynamic behavior from the wave–current interaction (WCI).