Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization

Abstract Estimates for roll damping are important input parameters for simulation studies on vessels operating at sea, e.g. FPSO mooring in waves, wind and current, workability and operability investigations, Dynamic Position studies, ship-to-ship operations and safety studies of vessels. To accurately predict the motions of vessels this quantity should be determined with confidence in the values. Traditionally, model experiments in water basins using so-called decay tests are carried out to determine the roll damping. With recent advancements in CFD modelling, the offshore industry has started using CFD as an alternative tool to compute the roll damping of FPSO’s. In order to help adopt CFD as a widely accepted tool, there is a need to develop confidence in CFD predictions. Therefore, a practical CFD modelling practice is developed within the Reproducible CFD JIP for roll decay CFD simulations. The Modelling Practice describes the geometry modelling, computational mesh, model set-up and post-processing for these type of CFD calculations. This modelling practice is verified and validated by three independent verifiers against available model test data. This paper provides an overview of the developed modelling practice and the calculated CFD results from the verifiers. The CFD modelling practice is benchmarked against available model test results for a tanker-shaped FPSO. By following this modelling practice, the CFD predictions for the equivalent linear damping coefficient and natural period of the roll motions are within 10% for all verifiers and within 10% from the model test results. Therefore, we conclude that when following the developed modelling practice for roll decay simulations, reliable, accurate and reproducible results can be obtained for the roll damping of tanker-shaped FPSOs.

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Addition of Tubifex accelerates dewatering of oil sands tailings

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0308 ◽

2016 ◽

Vol 43 (12) ◽

pp. 1025-1033 ◽

Cited By ~ 1

Author(s):

Xiaojuan Yang ◽

Miguel de Lucas Pardo ◽

Maria Ibanez ◽

Lijun Deng ◽

Luca Sittoni ◽

...

Keyword(s):

Oil Sands ◽

Land Reclamation ◽

Test Results ◽

Anionic Polymer ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Oil Sands Tailings ◽

Set Up ◽

Solids Content

Accelerating dewatering of fluid fine tailings (FFT) to facilitate land reclamation is a major challenge to the oil sands industry in Canada. A new method was tested, addition of Tubifex to FFT. Tubifex is an indigenous earthworm in Canada. The survival rate tests showed that Tubifex can survive in oil sands tailings and penetrate to 42 cm depth (maximum depth tested). Columns (5 L of FFT) were set-up with tailings alone, Tubifex treated tailings and polymer-Tubifex treated tailings. Test results showed that (a) the final mud–water interface of tailings alone was 26% higher than that of Tubifex treated tailings; (b) solids content of Tubifex treated tailings was 21% more than that of tailings alone; (c) Tubifex was capable to accelerate the dewatering process of both cationic and anionic polymer treated tailings; (d) anionic polymer was superior in facilitating long-term dewatering and its coupled effects with Tubifex were better than the cationic polymer.

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Comparative analysis of cycloid pump based on CFD and fluid structure interactions

Advances in Mechanical Engineering ◽

10.1177/1687814020973533 ◽

2020 ◽

Vol 12 (11) ◽

pp. 168781402097353

Author(s):

Wang Yanhua ◽

Huang Longlong ◽

Liu Yong ◽

Xu Jingsong

Keyword(s):

Model Building ◽

Contact Point ◽

Great Influence ◽

Test Results ◽

Fluid Structure Interactions ◽

Fluid Structure ◽

Mean Values ◽

Calculation Results ◽

Different Temperatures ◽

Set Up

At present, in the aspect of numerical simulation of cycloid pump, most studies focused on CFD (Computational Fluid Dynamics) in analyzing the pump performance under different service conditions (such as speed, temperature, etc.). The characteristics of the pump under FSI (Fluid Solid Interaction) have not been considered yet. By means of the dynamic mesh technique in the rotating domain, the fluid structure coupling interface is set up on a cycloidal pump model building in COMSOL. The simulation results obtained by applying CFD and FSI are improved by experimental verification. The results show that: (1) the average flow rate of FSI simulation is closer to the test results, and the mean values of CFD and FSI pressure are closer to the actual outlet boundary settings; (2) by comparing the velocity and pressure of rotation region of CFD and FSI at different temperatures, it is concluded that the pressure CFD calculated in the region is more than FSI, and the velocity CFD calculated is less than FSI; (3) by comparing the pressure distribution at some contact point of the fluid structure coupling interface, it is concluded that the fluctuation value of the pressure of CFD with time is greater than that of FSI. Through the comparison, it is found that the coupling has a great influence on the calculation results. The FSI analysis of the pump makes the analysis results more real and more conducive to the analysis of the flow field and rotor dynamics characteristics of the pump.

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The Research and the Development of the 3D System Platform of Shafting Parts Based on CAA

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.693.1886 ◽

2016 ◽

Vol 693 ◽

pp. 1886-1892 ◽

Cited By ~ 1

Author(s):

Hui Min Fang ◽

Gang Zhao ◽

Guo Zheng Zhang ◽

Ping Xiao

Keyword(s):

Secondary Development ◽

Test Results ◽

System Operation ◽

Development Environment ◽

Design Efficiency ◽

Development Platform ◽

Rapid Design ◽

Component Development ◽

Set Up

The enterprises when the designer worked with CATIA. In order to improve the efficiency, the research took the shaft parts as the research object to realize the secondary development of CATIA V5R18. The development platform of Shafting parts was set up through the embedded component development environment of CATIA CAA RADE and CAA API and was based on the development platform of VC++. At the end, this paper took the typical parts as examples to introduce the method of system operation. The test results show that this system could realize the rapid design and enhance the design efficiency, and it could provide the experience for the deeper development of CATIA.

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Research on Methods for Elastic Stiffness of Multi-Ribbed Slab Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.1736 ◽

2010 ◽

Vol 97-101 ◽

pp. 1736-1740

Author(s):

Qi Zhang ◽

Dong Bo Li ◽

Qian Feng Yao ◽

Dong Zhao

Keyword(s):

Time History ◽

Elastic Stiffness ◽

Structural Effect ◽

Time History Analysis ◽

Equivalent Model ◽

Test Results ◽

History Analysis ◽

Set Up

Considering the influence of the flange and rib column, the equivalent model of multi-ribbed slab is set up by the theory based on the strengthening isotropism fiber. This model is simple, highly precise and strongly applicable through comparing analyzing results with test results. Besides, the calculated formulate is set up on the basis of the whole structural effect and space work, which offers the prerequisite for elastic time history analysis of the structure.

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Improved Strake Design for Vortex Induced Motions of Spar Platforms

24th International Conference on Offshore Mechanics and Arctic Engineering: Volume 1, Parts A and B ◽

10.1115/omae2005-67384 ◽

2005 ◽

Cited By ~ 8

Author(s):

Mehernosh Irani ◽

Lyle Finn

Keyword(s):

Model Test ◽

Model Tests ◽

Test Results ◽

Test Program ◽

Test Set ◽

Test Methodology ◽

Spar Platforms ◽

Truss Spar ◽

Set Up

An extensive model test program was conducted to explore the effectiveness of alternate strake designs to reduce Truss Spar VIV response. Different strake configurations were tested to minimize VIV response. The paper presents results of the model tests. The model test set-up is described, important parameters that are modeled (including hull and truss geometry, strake configuration, mass and mooring properties) and considerations of instrumentation and test methodology are discussed. The paper also describes the analysis of the test results and shows the effectiveness of new strake design. The present results are compared with VIV response of existing Truss Spars with conventional strake design.

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Effects of Variations on the Experimental Set-Up on the Motion Response of a Floating Wind Semisubmersible (OC4 Type)

ASME 2019 2nd International Offshore Wind Technical Conference ◽

10.1115/iowtc2019-7543 ◽

2019 ◽

Author(s):

Sebastien Gueydon

Keyword(s):

Low Frequency ◽

Test Results ◽

Complex Behaviour ◽

Code Comparison ◽

Motion Responses ◽

Wave Basin ◽

Complex Test ◽

Inertia Properties ◽

Set Up ◽

Work Done

Abstract With their light weights, small components like braces and heave plates and steady trim angle caused by the wind loads acting on the rotor, semisubmersible foundations used as support platform for wind turbines exhibit a complex behaviour where viscous loading play an important role. The work done by the Offshore Code Comparison Collaboration Continued with Correlation (OC5) project has shown that standard engineering tools were not always able to predict accurately the motions of the DeepCwind semisubmersible that were measured in a basin. The correct amplitude of the motions at the natural periods of this system appeared to be difficult to obtain with simulations (especially the low frequency surge, and the pitch resonant motion). In view of the complexity of the system, it was not possible to clearly identify the causes of the differences between the simulations and the model-test results. A follow-on validation campaign was therefore performed at the Maritime Research Institute Netherlands (MARIN) under the MARINET2 project with the same floating substructure, with a focus on better understanding the hydrodynamic loads and reducing uncertainty in the tests by minimizing the system complexity. The wind turbine was replaced by a stiff tower with resembling inertia properties. The mooring system was simplified by using taut-spring lines with equivalent linear stiffness in surge. This paper reviews the new tests done with the simplified set-up and examines the differences with previous tests done with more complex test set-ups. The main motivation of this work is to study how variations of an experimental set-up can affect the outcome of tests in a wave basin. To start with, the main parameters of the systems (inertia, hydrostatics, and mooring stiffness) for all set-ups are characterized to check how similar they are. Then the level of damping in all systems is compared. Finally, the paper looks at how well the motion responses of this semisubmersible in waves correlate between all these campaigns.

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Porosity Measurement of Low Permeable Materials Using Gas Expansion Induced Water Intrusion Porosimetry (GEIWIP)

Scientific Reports ◽

10.1038/s41598-019-53441-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Miad Jarrahi ◽

Douglas W. Ruth ◽

Mohamed T. Bassuoni ◽

Hartmut M. Holländer

Keyword(s):

Lower Cost ◽

Test Results ◽

Field Site ◽

Preparation Time ◽

Water Intrusion ◽

Key Factor ◽

Set Up ◽

Gas Expansion ◽

Wetting Fluid ◽

Mobile Measurement

AbstractPorosity measurement is a key factor to identify the hydraulic performance of low permeable porous materials (e.g. rock or concrete). Porosimetry tests such as Mercury Intrusion Porosimetry (MIP), Nuclear Magnetic Resonance (NMR), or Gas Expansion (GE) are cost-prohibitive, use hazardous materials, or are incapable of accessing all inter-connected pores. An alternative Gas Expansion Induced Water Intrusion Porosimetry (GEIWIP) method was developed to measure the porosity of a low permeable porous medium using a gas/water intrusion apparatus. This method overcomes the previously mentioned porosimetry drawbacks by using distilled de-aired water (DDW) as a hazard-free liquid which is a wetting fluid to intrude the porous structure and fill the pores. As the DDW has the tendency to fill all inter-connected pores, no back-up pressure is required. This method has lower cost and needs less preparation time comparing to MIP test. Additionally, the GEIWIP set-up, the gas/water intrusion apparatus, can be moved to the field site and provide mobile measurement feasibility. The reliability of the test results was obtained by a repetitive testing process. The porosity of concrete samples with different mixtures was obtained and compared to those of MIP and NMR tests.

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On the evaluation of yield stress of soils for debris flow analysis

E3S Web of Conferences ◽

10.1051/e3sconf/20199205002 ◽

2019 ◽

Vol 92 ◽

pp. 05002

Author(s):

Carlos Besso ◽

Tácio Mauro Pereira de Campos

Keyword(s):

Debris Flow ◽

Yield Stress ◽

Mass Movement ◽

Flow Analysis ◽

Rheological Parameters ◽

Test Results ◽

Slump Test ◽

Acceleration And Deceleration ◽

Cheap Alternative ◽

Set Up

Debris flow materials behave as a fluid, hence its analysis requires rheological parameters such as yield stress and viscosity. Yield stress is associated to the start and the end of the mass movement downhill in the sense that it denotes the yield transition from the creep to the flow regime, i.e., passage from solid to fluid state. This paper presents an experimental study of the yield stress of a colluvium from Rio de Janeiro, through its determination in a modified set-up of the slump test and in a rotational parallel plate rheometer. Tests were performed in five different water contents above its liquidity limit, providing a fairly good relationship between yield stress and water content. While slump test provides yield stress related to the beginning of the movement (acceleration), rheometer results are related to flow's outset and stoppage. As a result, the percentual differences between yield stresses associated with acceleration and deceleration were less than 5% in all testes, which is related to the low hysteresis effect in the flow curves obtained in the rotational rheometer. Comparing the two methodologies, it is proposed a correction from rheometer to slump test results. Results obtained are compared with data presented in other studies involving soil's yield stress, showing a good acceptance of the slump test results as a cheap alternative to rheometers.

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