scholarly journals WAVE CLIMATE ANALYSIS FOR ENGINEERING PURPOSE

1976 ◽  
Vol 1 (15) ◽  
pp. 2 ◽  
Author(s):  
Hans H. Dette ◽  
Alfred Fuhrboter
Keyword(s):  
Wave Climate ◽  
Incoming Wave ◽  
Offshore Area ◽  
The North ◽  
Wave Measurements ◽  
Wind Velocities ◽  
Wave Heights ◽  
The North Sea ◽  
One Year ◽  
Climate Analysis

The North Sea (Fig. 1) is known as a random sea with depths in the southern part between 40 m and 100 m so that in contrary to the Atlantic and Pacific coastlines deep sea wave conditions do not exist. After four years of comprehensive wave measurements in the offshore area of the Island of Sylt near the Danish border a general analysis of the wave climate in that region was possible. In this paper results and suggestions will be presented under the aspect of replacing qualitative judgements by quantitative statements which are derived from the knowledge of the adjacent wave climate. Because the wave action varies from year to year a general time unit is not advisable for the evaluation of shore processes; therefore the time scale should be substituted by the integral of incoming wave energy occurring after a certain time. The investigated method of expressing the total energy of one season or one year in the electrical unit Kilowatthour (kWh) per meter (m) width of shoreline could prove in future as a feasible way of classifying the irregular seasonal and yearly wave intensities. It is further shown that wave measurements over a period of several years can be sufficient for the investigation of correlations between the wind velocities occurring from all directions and the resulting wave heights. In case of satisfying correlation factors it will then be possible to carry out feedback operations for periods from which only records of wind velocities and directions are available and even to hindcast the wave heights for certain not yet measured wind velocities.

scholarly journals HEIGHT DISTRIBUTION OF ESTUARINE WAVES

1982 ◽  
Vol 1 (18) ◽  
pp. 9
Author(s):  
V. Barthel
Keyword(s):  
North Sea ◽  
Rayleigh Distribution ◽  
Wave Climate ◽  
Field Investigation ◽  
Height Distribution ◽  
Empirical Distributions ◽  
The North ◽  
Wave Heights ◽  
The North Sea ◽  
Sea Wave

A field investigation program on waves was carried out in the Weser estuary, German Bight of the North Sea. Wave height and period distributions in this complicated wave climate can be approximated by a Rayleigh distribution. Empirical distributions of the wave heights characterise the different regions of the estuary. The presence of wave grouping as well as the group bounded long waves are shown in a few examples. The necessity of further investigations and analysis is highlighted.

scholarly journals STATISTICAL DISTRIBUTION OF WAVE HEIGHTS IN CORRELATION WITH ENERQ7 SPECTRUM AND WATER DEPTH

1964 ◽  
Vol 1 (9) ◽  
pp. 8
Author(s):  
L.A. Koele ◽  
P.A. De Bruyn
Keyword(s):  
Water Depth ◽  
Wave Motion ◽  
Statistical Distribution ◽  
Coastal Structures ◽  
Coastal Morphology ◽  
Delta Area ◽  
The North ◽  
Wave Measurements ◽  
Wave Heights ◽  
The North Sea

Wave motion has been studied at various places in the south western part of the Netherlands (the Delta area) as part of a study on coastal morphology and the design of coastal structures. The main part of this study deals with the statistical distribution of wave heights in relation to: a. the height of the sea surface at fixed points, as a function of time; b. the water depth; c. the energy spectrum of the wave motion. The results of theoretical studies by D.E.Cartwright and M.S.Longuet Higgins (lit. 1) and data on wave measurements obtained by Rijkswaterstaat in the North Sea were used. These measurements were taken by means of an electrical step-capacity gauge, with wireless transmission of the data to shore . Three gauges, fastened to fixed poles (named E, X and T) were placed at points at depths of 5, 10 and 15 meters respectively, (fig. 1).

scholarly journals North Atlantic storm driving of extreme wave heights in the North Sea

2017 ◽  
Vol 122 (4) ◽  
pp. 3253-3268 ◽  
Author(s):  
R. J. Bell ◽  
S. L. Gray ◽  
O. P. Jones
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Extreme Wave ◽  
The North ◽  
Wave Heights ◽  
The North Sea

Spectral wave climate of the North Sea

2007 ◽  
Vol 29 (3) ◽  
pp. 146-154 ◽  
Author(s):  
Alexander V. Boukhanovsky ◽  
Leonid J. Lopatoukhin ◽  
C. Guedes Soares
Keyword(s):  
North Sea ◽  
Wave Climate ◽  
The North ◽  
The North Sea

Performance Monitoring on the A˚sgard “A” FPSO as Part of an Integrated Monitoring Strategy

2002 ◽  
Author(s):  
Arne So̸rli ◽  
Kyrre Langnes ◽  
Geert Laagland ◽  
Mike Hastings
Keyword(s):  
Monitoring System ◽  
Performance Monitoring ◽  
Early Stage ◽  
Integrated Monitoring ◽  
The North ◽  
Stage Of Development ◽  
System Supplier ◽  
The North Sea ◽  
Condition Monitoring System ◽  
One Year

An integrated machine condition monitoring system was developed, installed, tested, commissioned and successfully operated on a floating production, storage and offloading vessel (FPSO) in the North Sea. This system combines an existing vibration and process monitoring system with focused performance monitoring capability that has been implemented with the cooperation of the oil company end-user, a thermodynamics specialist consultant and a monitoring system supplier. Implementation of this integrated monitoring system strategy with advanced performance monitoring is partly based on the end-user’s requirements to optimize their operation and maintenance functions to improve competitiveness. The system has already been in use for one year and has demonstrated the ability to detect faults at an early stage of development, such as the compressor degradation and gas turbine fouling described in this paper. The same system has also been implemented in other oil & gas and power applications around the world with similar, positive results.

Statistics of Greater Sea States

2011 ◽  
Author(s):  
Anne M. Fullerton ◽  
Thomas C. Fu
Keyword(s):  
Numerical Models ◽  
Ship Motions ◽  
Frequency Range ◽  
Sea State ◽  
The North ◽  
Spectral Models ◽  
Wave Heights ◽  
The North Sea ◽  
Computational Predictions ◽  
The Ideal

Accurate representations of seaway statistics are important for physical and computational predictions of ship motions. The spectra that are most typically used in these applications are the Pierson-Moskowitz or Bretschneider. While these spectra are useful for fully developed seas, the larger sea states (Sea State (SS) 7 and higher) are typically not fully developed. In these cases, other spectral models may be more appropriate. It is critical to ship motion prediction, for both physical and numerical models, to accurately capture the frequency range for the sea state of interest. Sea state statistics, including wave heights, periods, and spectral bandwidths from various buoys and a platform in the North Sea are collected and compared with statistics from lower sea states. The spectral data are then averaged to generate a typical spectrum under the measured conditions. These developed spectra are compared with the ideal spectra mentioned previously.

Impact of Climate Change on the North Sea Offshore Energy Sector

2018 ◽  
Author(s):  
Nicolas Fournier ◽  
Galina Guentchev ◽  
Justin Krijnen ◽  
Andy Saulter ◽  
Caroline Acton ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
North Sea ◽  
Wave Climate ◽  
Energy Industry ◽  
Strong Impact ◽  
Impact Of Climate Change ◽  
The North ◽  
Climate Indicators ◽  
The North Sea

The complex nature of the energy industry across extraction, transportation, processing, delivery and decommissioning creates significant challenges to how the sector responds, adapts and mitigates against risks posed by the changing future climate. Any disruption in this interconnected system will affect both industry and society. For example, in the summer of 2005 Hurricane Katrina and a month later Hurricane Rita had wide reaching impacts on the US offshore Oil and Gas industry which resulted in an increase in global oil prices due to loss of production and refinery shutdowns in the Gulf of Mexico. Preparing, mitigating and adapting to these climate changes is dependent upon identifying appropriate climate indicators as well as the associated critical operational thresholds and design criteria of the identified vulnerable assets. The characterization and understanding of the likely changes in these climate indicators will form the basis for adaptation plans and mitigating actions. The Met Office in collaboration with energy industry partners, under the Copernicus Clim4energy European project, has developed a Climate Change Risk Assessment tool, which allows the visualization and extraction of the most recent sea level and wave climate information to evaluate their future changes. This study illustrates the application of this tool for evaluation of the potential vulnerability of an offshore infrastructure in the North Sea. The analysis shows that for this asset there is a small increase in sea level of 0.20–0.30 m at the location of interest by 2050. However, there is a small decrease or no consistent changes projected in the future wave climate. This wave signal is small compared to the uncertainty of the wave projections and the associated inter-annual variability. Therefore, for the 2050s time horizon, at the location of interest, there is no strong impact of climate change at the annual scale on the significant wave height, the sea level and thus the associated climate change driven extreme water level. However, further analysis are required at the seasonal and monthly scales.

Using a Dacon Scoop to Recover a Loaded Liferaft at Sea

2013 ◽  
Author(s):  
Robert Brown ◽  
Kerri-Ann Evely ◽  
Graham Small ◽  
Scott MacKinnon
Keyword(s):  
North Sea ◽  
Human Factor ◽  
Effective Means ◽  
Field Trials ◽  
Safe Haven ◽  
Eastern Canada ◽  
The North ◽  
Wave Heights ◽  
The North Sea ◽  
Significant Wave Heights

Service and supply vessels that perform standby duties in the offshore sector are equipped with a variety of resources with which to perform rescue at sea. For light to moderate sea conditions, techniques currently understood and practiced tend to involve using a fast rescue craft (FRC) to rescue survivors and subsequently transfer them to a safe haven (often a standby vessel). Rescuing evacuees in higher, more challenging sea states, however, is difficult given that it can be unsafe to launch and recover FRCs in such conditions. For these cases, many standby vessels in Eastern Canada and the North Sea are equipped with a device called a Dacon Scoop. The Dacon Scoop is a 6 to 8m semi-rigid net that is deployed directly from the side of the standby vessel and designed to rescue people directly from the water. While not a conventional use, it has been suggested that the scoop could also be used to recover small rescue craft (life rafts, lifeboats and fast rescue craft) at sea. Although life rafts provide occupants with some protection from the elements, there are still issues that can make it less than desirable to remain inside for extended periods of time if an effective means of system recovery is available. This paper presents the findings of research carried-out to determine if it is safe to use a Dacon Scoop to recover a loaded liferaft. The research trials made use of a loaded inflatable 25 person davit launched life raft and two different standby vessels 75m in length. A total of 34 tests were carried out over three days in significant wave heights up to 3.7m. Recommendations are given in the context of a human factor assessment related to the procedures, equipment and field trials experiences.

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