Determination of Riser Tensioner Properties From Full-Scale Data

Author(s):  
Himanshu Gupta ◽  
Vincenzo Nava ◽  
Hugh Banon ◽  
Vasileios Gkaras ◽  
Pol Spanos

Tensioners are used for supporting various kinds of production and drilling risers on offshore platforms. All permanent production facilities (such as TLP’s and Spar’s) have employed tensioners to support their dry tree production risers. The key design parameters for the tensioners design are stiffness, stroke and friction properties. Full scale onshore testing of production riser tensioners to determine tensioner properties is difficult due to the magnitude of the loads and pressures required for typical deepwater risers, thus designers frequently rely on theoretical values or small scale tests. This paper presents a determination of riser tensioner properties from full scale offshore observations made on the Holstein Spar production facility during 2005 hurricance season. The paper presents a model for the tensioner system that relates the properties needed by platform and riser designers to the physical tensioner systems. The methodology and results from extraction of parameters from the full scale data is presented. The results presented in this paper will provide a better insight to the designers of such systems.

2010 ◽  
Vol 31 (11) ◽  
pp. 1191-1201 ◽  
Author(s):  
Jing‐Jie Yu ◽  
Guo‐Wei Gu ◽  
Giovanni Esposito ◽  
Massimiliano Fabbricino ◽  
Shao‐Po Wang ◽  
...  

Author(s):  
Horia Hangan ◽  
Maryam Refan ◽  
Djordje Romanic

This chapter introduces recent results aiming to compare full-scale data and simulations of tornadoes and to establish a framework through which simulations of tornado-like vortices (both physical and numerical) can be compared to full-scale data. Physical and sometimes numerical simulations of non-synoptic winds such as tornadoes and downbursts are performed at a reduced (model) scale (Λl) compared to reality (prototype). That approach implies that there is also a timescale (Λt) and a velocity scale (Λv) involved, and the three of them are interlinked. The proper determination of these scales is critical in the process of translating results from model simulations to reality. This chapter discusses the state of the art of determining these scales for two types of non-synoptic winds—tornadoes and downbursts.


2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.


1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.


2014 ◽  
Vol 955-959 ◽  
pp. 3393-3399 ◽  
Author(s):  
Wei Zheng ◽  
Yan Ming Yang ◽  
Yun Long Li ◽  
Jian Qiu Zheng

The process technique and design parameters of project of Solar Ozonic Ecological Sewage Treatment Plant (short for SOESTP) which consists of anaerobic reactor, horizontal subsurface flow (HSSF) constructed wetlands(CWs) and the combination of solar power and ozone disinfection are described, the paper further examines the removal efficiency for treating rural domestic sewage, running expense and recycling ability of product water. The results show that the average percentage removal values of CODcr,BOD5,SS,TN,NH3-N,TP range from 95.6% to 98.0%, 96.0% to 98.7%, 93.1% to 96.1%, 97.0% to 98.9%, 96.9% to 99.5%, 98.2% to 99.6%, respectively, the reduction of fecal coliform (FC) reaches 99.9%, the effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002). The running cost of SOESTP is 0.063yuan/ m3, saves much more than traditional sewage treatment, and the ozone water obtained from the reservoir will be an ideal choice for disinfection .The system has characteristics of easy manipulation, low operating cost, achieving advanced water, energy conservation and environment protection, is thought to be very suitable for use as the promotion of rural small - scale sewage treatment.


Author(s):  
D.M. Seyedi ◽  
C. Plúa ◽  
M. Vitel ◽  
G. Armand ◽  
J. Rutqvist ◽  
...  

2021 ◽  
Vol 11 (3) ◽  
pp. 908
Author(s):  
Jie Zeng ◽  
Panagiotis G. Asteris ◽  
Anna P. Mamou ◽  
Ahmed Salih Mohammed ◽  
Emmanuil A. Golias ◽  
...  

Buried pipes are extensively used for oil transportation from offshore platforms. Under unfavorable loading combinations, the pipe’s uplift resistance may be exceeded, which may result in excessive deformations and significant disruptions. This paper presents findings from a series of small-scale tests performed on pipes buried in geogrid-reinforced sands, with the measured peak uplift resistance being used to calibrate advanced numerical models employing neural networks. Multilayer perceptron (MLP) and Radial Basis Function (RBF) primary structure types have been used to train two neural network models, which were then further developed using bagging and boosting ensemble techniques. Correlation coefficients in excess of 0.954 between the measured and predicted peak uplift resistance have been achieved. The results show that the design of pipelines can be significantly improved using the proposed novel, reliable and robust soft computing models.


2012 ◽  
Vol 455-456 ◽  
pp. 284-288
Author(s):  
Wei Li Gu ◽  
Jian Xiang Liu

this paper studies the typical irreversible processes such as combustion and heat transfer with temperature difference based on the theory of thermodynamics, analyzes the influencing factors on exergy loss in irreversible processes, on the basis of this analysis, proposes the energy-saving optimization measures on design and operation management of the organic heat transfer material heater, and specially points out that in the design process, objective function can be constructed with the exergy loss as evaluation index to determine the outlet flue gas temperature of furnace and the flue gas temperature, and provides theoretical basis for the determination of design parameters.


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