Analysis of PIV Tests Results of the Vortex Self Induced Vibration (VSIV) of a Cylinder

2012 ◽  
Author(s):  
Antonio Carlos Fernandes ◽  
Sina Mirzaei Sefat ◽  
Luis V. Cascão ◽  
Ricardo Franciss
Keyword(s):  
Rio De Janeiro ◽  
Vertical Motion ◽  
Horizontal Cylinder ◽  
Elastic Support ◽  
Experimental Apparatus ◽  
Steel Catenary Risers ◽  
Floating Platforms ◽  
Oscillating Motion ◽  
Insight Into ◽  
Oval Shape

The Vortex Self Induced Vibration (VSIV) of cylinders is a phenomenon which occurs in the nature with devices such as Steel Catenary Risers (SRCs) in the deep offshore connected to floating platforms. The devices oscillate transversely due the own vertical motion. This is a currentless (therefore different form VIV) problem. To gain more insight into the nature of VSIV problem, an experimental apparatus was constructed which measure the transversal and response associated with vortex-induced vibration of a totally submerged horizontal cylinder hang on horizontally elastic support under the influence of vertical harmonic oscillating motion. The experiments were conducted in a tank at the LOC/COPPE/UFRJ (Laboratory of Waves and Current of COPPE, Federal University of Rio de Janeiro). The VSIV phenomena of the cylinder in different exciting amplitudes and exciting frequencies could generate different vertical trajectories of VSIV motion such as oval-shape, eight-shape and etc. This paper aims to describe the behavior of the flow around the cylinder during the VSIV motion based on the PIV tests on VSIV motion for different Keulegan-Carpenter numbers and for several exciting frequencies.

Further Investigations on Vortex Self Induced Vibration (VSIV)

2011 ◽  
Author(s):  
Antonio Carlos Fernandes ◽  
Sina Mirzaei Sefat ◽  
Luis Victor Casca˜o ◽  
Pedro Vilas Boas ◽  
Ricardo Francis
Keyword(s):  
Rio De Janeiro ◽  
Horizontal Cylinder ◽  
Elastic Support ◽  
Experimental Facility ◽  
Transversal Motion ◽  
Steel Catenary Risers ◽  
Floating Platforms ◽  
Oscillating Motion ◽  
A Current ◽  
Oval Shape

An experimental facility has been designed to study the transversal and response associated with vortex-induced vibration of a totally submerged horizontal cylinder hang on horizontally elastic support under the influence of vertical harmonic oscillating motion. The study aims to analyze the vortex self induced vibration (VSIV) phenomena, which occurs for instance with Steel Catenary Risers (SRCs) the deep offshore connected to floating platforms. These vibrations occur even in the absence of a current. The experiments were conducted in a tank at the LOC/COPPE/UFRJ (Laboratory of Waves and Current of COPPE, Federal University of Rio de Janeiro). The tests were carried out with Keulegan-Carpenter numbers equal to 10 and 20 and for several exciting frequencies. The vertical trajectories of the VSIV motion were then classified based on its different configurations such as oval-shape, eight-shape and etc. Different ranges of reduced velocities were also considered. The amplitude and frequency of transversal motion and also the forces calculated.

Onset of Natural Convection from a Suddenly Heated Horizontal Cylinder

1980 ◽  
Vol 102 (4) ◽  
pp. 636-639 ◽  
Author(s):  
J. R. Parsons ◽  
J. C. Mulligan
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Heat Capacity ◽  
Natural Convection ◽  
Stability Analysis ◽  
Horizontal Cylinder ◽  
Finite Cylinder ◽  
Global Motion ◽  
Experimental Apparatus

A study of the onset of transient natural convection from a suddenly heated, horizontal cylinder of finite diameter is presented. The termination of the initial conductive and “locally” conuectiue heat transfer regime which precedes the onset of global natural convection is treated as a thermal stability phenomenon. An analysis is presented wherein the effects of finite cylinder diameter, cylinder heat capacity, and cylinder thermal conductivity are included in calculations of the convective delay time. A simple experimental apparatus is described and data presented. The thermal stability analysis is confirmed experimentally and data is presented which indicates localized natural convection prior to global motion.

scholarly journals Molecular diversity of Mycobacterium tuberculosis strains in a slum area of Rio de Janeiro, Brazil

2008 ◽  
Vol 34 (12) ◽  
pp. 1063-1068 ◽  
Author(s):  
Joycenea Matsuda Mendes ◽  
Silvia Maria Almeida Machado ◽  
Maria Cristina Lourenço ◽  
Rosa Maria Carvalho Ferreira ◽  
Leila de Souza Fonseca ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Rio De Janeiro ◽  
Insertion Sequence ◽  
Fragment Length Polymorphism ◽  
Control Program ◽  
Molecular Study ◽  
Tuberculosis Control ◽  
Primary Resistance ◽  
The City ◽  
Insight Into

This retrospective molecular study involving restriction fragment length polymorphism, using insertion sequence 6110 as a marker, was conducted in order to provide an initial insight into the genetic diversity of Mycobacterium tuberculosis strains isolated in the slums of the Complexo de Manguinhos, located in the city of Rio de Janeiro, Brazil. Of the 67 strains evaluated, 23 (34.3%) were found to belong to clusters (total clusters, 10). Household and social chains of transmission were associated with clustering, in 20% and 60%, respectively. Living in the Conjunto Habitacional Programado 2 slum was associated with clustering. Although not significant, it is relevant that 26% of the clustered strains presented primary resistance. These findings, although possibly underestimating the prevalence due to the failure to analyze all strains, could help improve the local tuberculosis control program.

Steel Lazy Wave Riser Optimization Using Artificial Intelligence Tool

2020 ◽  
Author(s):  
Mayank Lal ◽  
Abhilash Sebastian ◽  
Feng Wang ◽  
Xiaohua Lu
Keyword(s):  
Artificial Intelligence ◽  
Genetic Algorithm ◽  
Design Process ◽  
Oil And Gas ◽  
Time Domain Analysis ◽  
Fatigue Performance ◽  
Wave Form ◽  
Steel Catenary Risers ◽  
Performance Drivers ◽  
Floating Platforms

Abstract Use of steel lazy wave risers has increased as oil and gas developments are happening in deeper waters or in parts of the world with no pipeline infrastructure. These developments utilize FPSO’s with offloading capabilities necessary for these developments. However, due to more severe motions compared to other floating platforms, traditional catenary form of risers are unsuitable for such developments and this is the reason Steel lazy wave risers (SLWR) are required. SLWRs have shown to have better strength and fatigue performance and lower tensions at the hang-off compared to steel catenary risers. A suitable Lazy-Wave form of the catenary riser is achieved by targeted placement of a custom configured buoyancy section. The strength and fatigue performance of steel lazy wave risers are governed by parameters such as length to start of this buoyancy section, length of the buoyancy section, hang-off angle and the buoyancy factor. Achieving these key performance drivers for a SLWR takes several iterations throughout the design process. In this paper, genetic algorithm which is an artificial intelligence optimization tool has been used to automate the generation of an optimized configuration of a steel lazy wave riser. This will enable the riser designer to speed up the riser design process to achieve the best location, coverage and size of the buoyancy section. The results that the genetic algorithm routine produces is compared to a parametric study of steel lazy wave risers varying the key performance drivers. The parametric analysis uses a regular wave time domain analysis and captures trends of change in strength and fatigue performance with change in steel lazy wave parameters.

scholarly journals A monument to Lazarus: the leprosy hospital of Rio de Janeiro

2003 ◽  
Vol 10 (suppl 1) ◽  
pp. 143-160 ◽  
Author(s):  
Thomas Hunter Smith III
Keyword(s):  
Rio De Janeiro ◽  
Church And State ◽  
Medical Science ◽  
Public Health Issue ◽  
Health Care Professions ◽  
African Slaves ◽  
History Of ◽  
Complex Relationships ◽  
The City ◽  
Insight Into

Soon after the Portuguese made landfall in 1500, Europeans and, later, African slaves introduced leprosy, and Saint Lazarus, the patron saint of its victims, into Brazil. Social and political pressure mounted by the middle of the eighteenth century in the city of Rio de Janeiro to remove those unfortunates from the city's streets even before the move of Brazil's capital in 1763. Frei Antônio, the bishop of Rio, founded the venerable hospital that year in the neighborhood of São Cristóvão. He requested that the Irmandade do Santíssimo Sacramento da Candelária provide oversight and administration. The brotherhood continues to honor its covenant of 239 years ago. The history of this hospital provides insight into the complex relationships that existed between the citizenry and church and state. Rio's leprosy hospital, now the Hospital Frei Antônio, had an important role in the evolution of the health care professions, progress in medical science, and the genesis of the hygienic movement in Brazil. This study also contributes to the history of a disease that persists in 2002 Brazil as a public health issue.

Development and Qualification of Alternative Solutions for Improved Fatigue Performance of Deepwater Steel Catenary Risers

2007 ◽  
Author(s):  
Rajiv K. Aggarwal ◽  
Marcio M. Mourelle ◽  
Steinar Kristoffersen ◽  
Henri Godinot ◽  
Pedro Vargas ◽  
...  
Keyword(s):  
Laboratory Testing ◽  
Fatigue Testing ◽  
High Strength ◽  
Operating Conditions ◽  
Fatigue Performance ◽  
Steel Catenary Riser ◽  
Regulatory Bodies ◽  
Steel Catenary Risers ◽  
Floating Platforms ◽  
Floating Systems

Several initiatives have been undertaken by the operators, engineering companies, product manufacturers, and regulatory bodies to enable increased use of steel catenary riser (SCR) design in development of deepwater and ultra-deepwater fields. Some of these efforts focus on improvement in understanding of soil-structure interaction at SCR touch down zone (TDZ) and its impact on fatigue damage estimates through analytical studies, laboratory testing, or in-field monitoring of SCR behavior. Through recent studies and laboratory testing work for floating platforms with SCR, the need for significant enhancement of SCR design at TDZ through implementation of alternate solutions has been identified. This paper presents a summary of the work undertaken in a Joint Industry Project (JIP) during 2004 to 2007 [1, 2] to develop solutions and undertake qualification tasks for four alternatives with potential to improve fatigue performance at TDZ by factor of up to 10 or more. The solutions considered at SCR TDZ include: thick light-weight coating over steel riser sections; steel riser sections with upset ends; high strength steel riser sections with integral connectors; and a titanium segment. The major qualification tasks undertaken for each solution will be identified and discussed. The qualification program undertaken for each solution varied and in some cases, it also included manufacturing of samples, laboratory and full-scale fatigue testing, and post-failure evaluation. Through significant qualification activities undertaken in this JIP, progress has been made to bring these solutions to project ready state for their consideration at the frond end engineering design (FEED) stage. Such design enhancements would enable increase in selection of SCR design for production and export riser applications under severe operating conditions, harsh environment, and floating systems with high motions.

scholarly journals Water Waves Provide Insight Into Landslides and Avalanche Models

Eos ◽  
2015 ◽  
Vol 96 ◽  
Author(s):  
David Shultz
Keyword(s):  
Gravity Waves ◽  
Water Waves ◽  
Granular Flows ◽  
Vertical Motion ◽  
Insight Into ◽  
Avalanche Models

Boussinesq-type gravity waves appear to accurately describe vertical motion in granular flows found in geophysics.

Sleeved Stress Joint for Steel Catenary Riser Application

2010 ◽  
Author(s):  
S.-H. Mark Chang ◽  
Paul Stanton ◽  
Sunil Kuriakose ◽  
Hugh Thompson
Keyword(s):  
Bending Moment ◽  
Variable Stiffness ◽  
Floating Platform ◽  
Steel Catenary Riser ◽  
High Fatigue ◽  
Steel Catenary Risers ◽  
Design Requirements ◽  
Floating Platforms ◽  
Oil Gas ◽  
Economical Alternative

Steel catenary risers (SCRs) have been widely used for oil/gas/water transport on floating platforms for the last fifteen years. Flex joints and tapered stress joints are often used for interface between the SCR and platform. Flex joints and tapered stress joints need to be designed to meet both the stiffness and flexibility requirements. A stress joint requires high stiffness to withstand the bending moment induced by the SCR and at the same time needs to be sufficiently flexible so as not to overstress the SCR. To achieve these complex requirements, a sleeved stress joint (SSJ) provides a sound technical and economical alternative for the interface between the SCR and platform. A sleeved stress joint utilizes multiple pipes to provide variable stiffness and to meet the strength and flexibility requirements. In the design of a SSJ, the number of sleeves, and the outer diameters and wall thicknesses of the sleeved pipes can be adjusted to achieve the design requirements. In addition, the locations of welds in the sleeved pipes can be placed to achieve the high fatigue performance that is important in stress joint design. Feasibility of the SSJ design is verified through state-of-the-art computer modeling. Generic cases of SSJ design applied to the porch and pull tube of a floating platform are presented. The design concept is compared with traditional flex joint and tapered stress joint designs. The technical and economic advantages of such a design are discussed.

A Parametric Study on Effects of Environmental Loadings on Fatigue Life of Steel Catenary Risers (Using a Nonlinear Cyclic Riser-Soil Interaction Model)

2010 ◽  
Author(s):  
Mehrdad Kimiaei ◽  
Mark Randolph ◽  
Ivan Ting
Keyword(s):  
Fatigue Damage ◽  
Deep Water ◽  
Interaction Model ◽  
Fatigue Assessment ◽  
Wide Range ◽  
Non Linear ◽  
Wave Heights ◽  
Steel Catenary Risers ◽  
Vessel Motion ◽  
Floating Platforms

Steel catenary risers (SCRs) are often the preferred option for subsea tie-back to floating platforms in deep water due to their conceptual simplicity, ease of construction and installation and simple interface with the flowlines. Fatigue design of SCRs, particularly in the touch down area (TDA), has always been one of the major engineering challenges. Traditionally, fatigue assessment of SCRs has usually been highly conservative, because of lack of precise understanding of the non-linear soil-riser-interaction in the TDA. Most fatigue studies are based on assumed linear stiffness for the seabed, partly because of the lack of robust non-linear riser-seabed interaction models and partly because the linear response simplifies the fatigue study. The recent availability of non-linear seabed response models provides an opportunity to improve fatigue assessment, but it is first necessary to evaluate how best to conduct fatigue studies for such nonlinear systems which can be sensitive to wide range of input parameters. This paper outlines a new advanced numerical model, considering nonlinear cyclic riser-soil interaction behavior, used to determine the contribution of different loading parameters on fatigue damage of SCRs in the TDA in deep water soft sediments. The main loading parameters considered are: different motions of floating vessels, wave heights, wave periods and wave packs ordering. Numerical modeling has shown that over 95% of the fatigue damage corresponds to floating vessel motion parallel to the riser axis at the connection point to the vessel. It is also shown that riser response at TDA is highly influenced with amplitude and period of the environmental loadings.

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