Experimental Set-Up for Analysis of Subsea Equipment Installation

2011 ◽  
Author(s):  
Pedro C. de Mello ◽  
Felipe Rateiro ◽  
Andre´ L. C. Fujarra ◽  
Anderson T. Oshiro ◽  
Cassiano R. Neves ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Companion Paper ◽  
Scale Model ◽  
Illustrative Case ◽  
Preliminary Evaluation ◽  
Hydrodynamic Properties ◽  
Wave Basin ◽  
Servo Actuator ◽  
Induced Motion ◽  
Reduced Scale

This paper and the companion paper (Rateiro et al., 2011) present an illustrative case of the joint application of experimental tests and numerical simulations for the proper analysis of a complex offshore operation (launching of a sub-sea equipment using one or two vessels). The main idea of the whole study is to compare two methodologies and operational procedures for the installation of the equipment in the seabed, using either one vessel (conventional operation) or two vessels in a synchronized operation in a Y-configuration. The experiment was conducted under a simplified configuration, and uses ODF (one degree of freedom) servo-actuator to emulate the vessels induced motion. The hydrodynamic properties of the equipment was then calculated, and some preliminary conclusions about system dynamics could also be drawn. After that, numerical simulations were conducted, considering the coupled dynamics of the vessels, cables and equipments under irregular sea state. Those simulations were used for determining the limiting environmental condition for a safe operation, and are described in the companion paper. This paper describes the reduced scale experimental setup used for evaluating the hydrodynamic properties of the equipment during a subsea installation under waves excitation. The reduced scale model of the equipment was attached to one or two servo-actuator, that emulate the wave-induced motion. The tests were conducted at the physical wave basin of Numerical Offshore Tank (Tanque de Provas Nume´rico – TPN). The experiments enabled the preliminary evaluation of the dynamic behavior of the equipment when submerged by one or two launching cables. In the later case (two launching cables), several tests considering phase shifts between the servo-actuator have been conducted. The reduction in the dynamic amplification of cable traction could also be experimentally verified.

Hydrodynamic Response of Three Column Semi-Submersible Floater Supporting Vertical Axis Wind Turbine

2017 ◽  
Author(s):  
Rajeswari Krishnan ◽  
Nallayarasu Seeninaidu
Keyword(s):  
Numerical Simulations ◽  
Wind Turbine ◽  
Wind Farms ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Scale Model ◽  
Vertical Axis Wind Turbine ◽  
Ocean Engineering ◽  
Motion Response ◽  
Wave Basin

Offshore wind energy extraction has gathered momentum around the world due to its advantages over onshore wind farms at various fronts. The floating support system with vertical axis wind turbine might prove to be feasible concept in medium to deep waters. In this context, this paper addresses an investigation of hydrodynamic analysis of three column semi-submersible with Vertical Axis Wind Turbine (VAWT) in parked condition under regular and random waves. Free decay experiments were conducted for using scale model (1:75) in a laboratory wave basin at the Department of Ocean Engineering in Indian Institute of Technology Madras, India. Computational Fluid Dynamics (CFD) simulations were used to assess damping characteristics and validated with the experiments. Numerical simulations of hydrodynamic motion response of the floater were carried out using potential flow theory based commercial software (ANSYS AQWA). The damping values obtained from experiments were used in numerical simulations to obtain motion response and Response Amplitude Operator (RAO). The motion response obtained from the study was used to verify the suitability of the system for deployment in east and west coast of India.

A Model Experiment of a Free Standing Riser in the Deep-Sea Basin

2013 ◽  
Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  
Keyword(s):  
Deep Sea ◽  
Model Experiment ◽  
Scale Model ◽  
Vertical Pipe ◽  
Free Standing ◽  
Visual Measurement ◽  
Smooth Cylinder ◽  
Induced Motion ◽  
Reduced Scale ◽  
A Current

An experiment using a 1/70 reduced scale model of a Free Standing Riser (FSR) was carried in the Deep-Sea Basin of the National Maritime Research Institute in Japan. For instance, the model’s vertical pipe was about 32m long and the jumper was about 8m long. The FSR model had several measurement stations attached along the vertical pipe, subsurface buoy and jumper; and the motion of each station was measured in 3D by the Visual Measurement System. During the experiment, the effects of the jumper’s top end oscillation on the whole system were investigated. In this case, the top oscillation had propagated along the jumper; however the top oscillation had a reduced effect on the dynamics of the subsurface buoy and vertical pipe. In another experimental case, a current was generated in order to investigate the Vortex Induced Motion (VIM) on the FSR’s Subsurface Buoy. The VIM experiment was repeated for two different buoy models (a smooth cylinder and a cylinder with 3-start heli-coidally strakes) and the results were compared. In this article, some of the experimental results are presented and discussed.

scholarly journals Uplift Bearing Capacity of Cone-Cylinder Foundation for Transmission Line in Frozen Soil Regions, Using Reduced-Scale Model Tests and Numerical Simulations

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2066
Author(s):  
Yangchun Han ◽  
Jiulong Cheng ◽  
Qiang Cui ◽  
Qianyun Dong ◽  
Wanting Song
Keyword(s):  
Transmission Line ◽  
Numerical Simulations ◽  
Bearing Capacity ◽  
Frozen Soil ◽  
Scale Model ◽  
Three Dimension ◽  
Scale Modeling ◽  
Bottom Width ◽  
The Impact ◽  
Reduced Scale

In order to analyze the uplift bearing capacity of cone-cylinder foundation for transmission line in frozen soil regions, a series of reduced-scale modeling tests and numerical simulations are carried out. First, three reduced-scale cone-cylinder foundations with the same sizes, that are five times smaller than the prototype, are made and then loaded under uplift load at −5 °C, −10 °C, and −15 °C, respectively. On this basis, the foundations of nine sizes are modeled and loaded by numerical simulation. The impact of three dimension factors, including the ratio of depth to bottom width ( λ = h t / D t ), the top diameter of the cone-cylinder (d), and the bottom diameter of the cone-cylinder (D), on the uplift bearing capacity of foundations have been investigated. The results reveal that, for cone-cylinder foundation, the uplift bearing capacity is obviously affected by the freezing temperatures and the foundation sizes. The capacity is negatively correlated with the former. Whereas the order of correlation with the latter is as follows: λ, D, and d based on the comprehensive results of range and variance analysis, but none of them are the significant factors, according to the F-test. Furthermore, three failure mechanisms of frozen soil are distinguished and named T-mode, V-mode, and U-mode, respectively. Based on the above results, the bearing mechanism of cone-cylinder foundation in frozen soil is elaborated in detail.

Structural Analysis for a Reduced Scale Model of a Hydropower Plant Debris Containment Grid

2017 ◽  
Author(s):  
Felipe Santos de Castro ◽  
Eduardo Tadashi Katsuno ◽  
Andre Mitsuo Kogishi ◽  
José Marcos Paz de Souza ◽  
Joao Lucas Dozzi Dantas Dantas
Keyword(s):  
Structural Analysis ◽  
Hydropower Plant ◽  
Scale Model ◽  
Plant Debris ◽  
Reduced Scale

Simulation of a Free Standing Riser Model and Validation With Experimental Results

2014 ◽  
Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Previous Experiment ◽  
Numerical Results ◽  
Experimental Results ◽  
Previous Article ◽  
Scale Model ◽  
Analysis Software ◽  
Free Standing ◽  
Reduced Scale

In this article, we present the numerical analysis of a Free Standing Riser. The numerical simulation was carried out using a commercial riser analysis software suit. The numerical model’s dimensions were the same of a 1/70 reduced scale model deployed in a previous experiment. The numerical results were compared with experimental results presented in a previous article [1]. Discussion about the model and limitations of the numerical analysis is included.

A Study of Aspiration Effects in Reduced-Scale Model Airbag Modules

1998 ◽  
Author(s):  
Y. G. Lee ◽  
C. S. Yu ◽  
P. W. Green ◽  
L.-D. Chen ◽  
P. B. Butler
Keyword(s):  
Scale Model ◽  
Reduced Scale

Reduced Model Device of Solutions to Control Thermal Buckling Effects in HP-HT Subsea Pipelines

2008 ◽  
Author(s):  
Helio C. Silva-Junior ◽  
Carlos O. Cardoso ◽  
Marco A. P. Carmignotto ◽  
Jose C. Zanutto
Keyword(s):  
Imaging Technique ◽  
Thermal Buckling ◽  
Scale Model ◽  
Reduced Model ◽  
Safe Operation ◽  
High Pressure And Temperature ◽  
Model Geometry ◽  
Subsea Pipelines ◽  
Model Device ◽  
Reduced Scale

Nowadays, the safe operation of HP-HT subsea pipelines resting on seabed must take into account the thermal buckling phenomenon. The transport of oil with high pressure and temperature can cause uncontrolled thermal buckling in subsea pipelines. The failure risk must be carefully evaluated to design the pipeline with safety. Nowadays to control the thermal buckling the use of man made triggers is seen like the best solution for cost and safety of subsea pipelines. Some projects employ man-made triggers to control the thermal buckling in the last years around the world. In this article is presented the system and methodology used to test some solutions in a reduced scale model. Different geometric setups along the model line were tested. Solutions like sleepers, dual sleepers and buoyancy were tested and the geometric and structural behavior monitored. The reduced model has 195 m length, and was developed in the IPT Towing Tank, representing a pipeline section of almost 6 km long. Strains, temperature, pressure and displacements were measured in several sections of the model. Additionally, an imaging technique for the model geometry retrieval was developed. This paper presents the experimental setup developed to investigate the performance of man-made triggers solutions for HP-HT subsea pipelines.

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