Numerical Simulation of Motion Response of Multi-Floating Body System Considering Different Gap Between TLP and TAD

2020 ◽  
Author(s):  
Zhigang Zhang ◽  
Shanjun Bao ◽  
Zhaogang Ding ◽  
Zhiyuan Wei ◽  
Haibo Sui ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Floating Body ◽  
Engineering Practice ◽  
Mooring System ◽  
Floating Bodies ◽  
Motion Response ◽  
Significant Difference ◽  
Drilling Operations ◽  
Drilling System ◽  
Simulation Results

Abstract Tender-assisted drilling system meets the strict requirements of deck space of the drilling platform, and provides a relatively safe and comfortable working environment for the staff, which has been widely used in drilling operations in recent years. The significant difference between multi-floating body and single offshore platform is that there may be risk of collision between the floating bodies under extreme metocean conditions or in emergency of mooring system failure. In order to prevent the collision during drilling operations, the initial gap between floating bodies should be designed carefully and provide a reasonable scheme to ensure the safety of the drilling system and the feasibility of drilling operations. Therefore, based on the three dimensional potential flow theory, frequency domain and time domain numerical simulation of the motion response of TLP and TAD is carried out according to the marine environment of West Africa with extreme metocean conditions, the effect of different initial gap on the motion performance of floating bodies is explored and the mechanical characteristics of the mooring system are analyzed. Thus, the reasonable initial gap between TLP and TAD is determined by comparing the simulation results. In general, the numerical simulation results of tender-assisted drilling system may provide reference for engineering practice to some extent.

scholarly journals Discussion on the Theoretical Basis for Cross-Over Method Applied to Downhole Wave Velocity Test

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qing Dong ◽  
Zheng-hua Zhou ◽  
Su Jie ◽  
Bing Hao ◽  
Yuan-dong Li
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Wave Velocity ◽  
Theoretical Basis ◽  
Influence Factors ◽  
P Wave ◽  
Engineering Practice ◽  
S Wave ◽  
Simulation Results ◽  
The Cross

At engineering practice, the theoretical basis for the cross-over method, used to obtain shear wave arrival time in the downhole method of the wave velocity test by surface forward and backward strike, is that the polarity of P-wave keeps the same, while the polarity of S-wave transforms when the direction of strike inverted. However, the characteristics of signals recorded in tests are often found to conflict with this theoretical basis for the cross-over method, namely, the polarity of the P-wave also transforms under the action of surface forward and backward strike. Therefore, 3D finite element numerical simulations were conducted to study the validity of the theoretical basis for the cross-over method. The results show that both shear and compression waves are observed to be in 180° phase difference between horizontal signal traces, consistent with the direction of excitation generated by reversed impulse. Furthermore, numerical simulation results prove to be reliable by the analytic solution; it shows that the theoretical basis for the cross-over method applied to the downhole wave velocity test is improper. In meanwhile, numerical simulations reveal the factors (inclining excitation, geophone deflection, inclination, and background noise) that may cause the polarity of the P-wave not to reverse under surface forward and backward strike. Then, as to reduce the influence factors, we propose a method for the downhole wave velocity test under surface strike, the time difference of arrival is based between source peak and response peak, and numerical simulation results show that the S-wave velocity by this method is close to the theoretical S-wave velocity of soil.

scholarly journals MOTION RESPONSE CHARACTERISTICS OF THE LARGE-SCALE FLOATING BODY MOORED BY ELASTIC MOORING SYSTEM

2020 ◽  
Vol 76 (2) ◽  
pp. I_390-I_395
Author(s):  
Hiroaki ETO ◽  
Hitomi KASHIMA ◽  
Ryo SEKIGUCHI ◽  
Tomoki IKOMA ◽  
Yasuhiro AIDA ◽  
...  
Keyword(s):  
Large Scale ◽  
Floating Body ◽  
Mooring System ◽  
Motion Response ◽  
Response Characteristics

Numerical simulation of the mooring capacity comparison of the subsea suspended manifold with two mooring schemes

2022 ◽  
pp. 147509022110701
Author(s):  
Ning Xu ◽  
Honglin Zhao ◽  
Yufang Li ◽  
Yingying Wang ◽  
Shimin Zhang
Keyword(s):  
Numerical Simulation ◽  
Production System ◽  
System Model ◽  
Mooring System ◽  
Conceptual Scheme ◽  
Fluid Density ◽  
Next Generation ◽  
Motion Response ◽  
Steel Catenary Riser ◽  
Steep Wave

The next-generation underwater production system (NUPS) is based on the suspension cluster manifold (SCM) as a new conceptual scheme. SCM mooring stability is essential for establishing NUPS. Therefore, comparing the SCM mooring stability in different mooring systems is vital for evaluating system adaptability. This paper detailed two mooring schemes designed for the SCM, including the steel catenary riser (SCR) mooring system and the new steep wave (NSWR) mooring system. OrcaFlex software was used to establish the mooring system model, analyzing the static motion response of the SCM under the current and fluid density. Furthermore, the mooring system adaptability in the cluster wellhead layout was also evaluated and compared. The results showed that the maximum offset of the SCM with the SCR mooring system was within 2 m under the current, while the deflection of the SCM with the NSWR mooring system was within 1.5° in extreme fluid densities. Furthermore, the SCM with the SCR mooring system displayed superior station-keeping capability in the current, while the NSWR mooring system exhibited better stability when transporting extreme fluid densities and was more adaptable in cluster wellhead layouts.

Study on Collision Forces on Water-Front Facilities Induced by Floating Vessels Washed Onto Apron by Tsunami

2010 ◽  
Author(s):  
Koichi Masuda ◽  
Mitsuhiro Masuda ◽  
Tomoki Ikoma
Keyword(s):  
Numerical Simulation ◽  
Floating Body ◽  
Present Calculation ◽  
Floating Bodies ◽  
Floating Structures ◽  
Mps Method ◽  
Calculation Results ◽  
Moving Particle ◽  
Collision Force ◽  
Water Front

The present paper describes the application of the moving particle semi-implicit method to a prediction of collision forces on water-front facilities induced by floating vessels washed onto the apron by tsunami. Effectiveness of the application is verified. Solitary waves are applied to simulated tsunamis in numerical simulation and to the model experiments. A pontoon type floating body is applied to floating structures in numerical simulations using the MPS method. The present calculation results are compared with the experimental results and the applicability of MPS method is discussed. Further, after being washed onto the wharf by tsunami, the characteristics of collision force on water-front facilities induced by the floating bodies are discussed.

Mooring Effect on Wave Frequency Response of Round Shape FPSO

2015 ◽  
Vol 74 (5) ◽  
Author(s):  
C. L. Siow ◽  
J. Koto ◽  
H. Yasukawa ◽  
A. Matsuda ◽  
D. Terada ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Model Experiment ◽  
Wave Frequency ◽  
Mooring System ◽  
Simulation Test ◽  
Mooring Lines ◽  
Motion Response ◽  
Motion Data ◽  
Model Scale ◽  
Round Shape

This paper presents the motions response of moored Round Shape FPSO model due to the wave effect. The proposed of this research is analyzed the possibility of model motion response affected by different mooring system attach to the model. Model experiment was applied in this research to collect motion data for the study. Besides, the numerical simulation using diffraction potential, diffraction potential with Morison Heave correction and ANSYS frequency domain study were also applied in this research to generate comparative data to the experimental results. To investigate the effect of the mooring system to motion response, the model experiment was firstly conducted by attached model scale catenary mooring lines to Round Shape FPSO model. After that, the experiment was repeated by attached model scale taut mooring lines to the same model. The results obtain from the regular wave experiment tests and numerical simulation test were presented in this paper. This research concluded that the mooring systems would not give significant effect to wave frequency motion response after compared the motion result obtain from model experiment conducted using different mooring system.  

scholarly journals Optimization of a cable support strategy for roadways in coal mines by using the PSO algorithm

2021 ◽  
Author(s):  
Zhu Tang ◽  
Shuqing Li ◽  
Fei Huang ◽  
Junwei Yang ◽  
Fuling Yang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Particle Swarm Optimization ◽  
Coal Mines ◽  
Pso Algorithm ◽  
Engineering Practice ◽  
Lateral Stress ◽  
Swarm Optimization ◽  
Support Strategy ◽  
Simulation Results ◽  
Roadway Support

Abstract Cables are commonly used for roadway support in coal mines. Traditionally, support schemes show characteristics of excessive strength and resource waste; therefore, determining how to scientifically and economically arrange the distribution of cables is important for engineering practice. To obtain the best distribution of cables, in this paper, the particle swarm optimization (PSO) algorithm and FLAC3D numerical simulation were combined to conduct numerical simulations. Finally, the best cable distribution considering safety and economy was determined. By analyzing the numerical simulation results, it can be concluded that the PSO algorithm can be applied to determine the optimal cable distribution for roadway support and can be applied to engineering practice. In addition, the best cable arrangement of a roadway under different lateral stress coefficients was obtained, and it can be concluded that the cable arrangement should be adjusted according to specific circumstances.

Numerical simulation experiments and regression modeling for asperity contact of ceramic surfaces

SIMULATION ◽  
2021 ◽  
pp. 003754972098788
Author(s):  
Yanqing Tan ◽  
Chengshun Li
Keyword(s):  
Numerical Simulation ◽  
Calculation Model ◽  
Engineering Practice ◽  
Ceramic Surface ◽  
Simulation Experiments ◽  
Ceramic Surfaces ◽  
Simulation Calculation ◽  
Surface Contact ◽  
Simulation Results ◽  
Contact Parameters

Ceramic materials, with their excellent properties, have been widely used in the engineering field. With the ceramic surface as the research object, the properties of elastic contact of ceramic surfaces are studied using the numerical simulation calculation method. In this paper, uniform experimental design is carried out with topography parameters, external load, and material property parameters, which have a direct impact on the surface contact; a numerical calculation model is established and a series of simulation experiments is carried out on the contact of asperities on the ceramic surface, which not only intuitively shows the contact behavior of asperities on the ceramic surface, but also obtains the contact parameters of the surface. Then, the numerical simulation results are compared with those of G-W model, which proves the feasibility of the numerical simulation calculation and shows that the numerical simulation model established in this paper is more in line with the engineering practice than the G-W model. Through the regression analysis of the simulation results, the analytical calculation model between the surface contact parameters and the influencing factors is established, which provides references for quantitative analysis and characterization of contact properties related to the material surface.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Non-stationary process characteristics of the gas outflow into a liquid

2019 ◽  
Vol 14 (2) ◽  
pp. 82-88
Author(s):  
M.V. Alekseev ◽  
I.S. Vozhakov ◽  
S.I. Lezhnin
Keyword(s):  
Numerical Simulation ◽  
Liquid Column ◽  
Gas Content ◽  
Liquid Lead ◽  
Gas Flows ◽  
Asymptotic Model ◽  
Process Characteristics ◽  
Significant Difference ◽  
Order Of Magnitude ◽  
Volume Method

A numerical simulation of the process of the outflow of gas under pressure into a closed container partially filled with liquid was carried out. For comparative theoretical analysis, an asymptotic model was used with assumptions about the adiabaticity of the gas outflow process and the ideality of the liquid during the oscillatory one-dimensional motion of the liquid column. In this case, the motion of the liquid column and the evolution of pressure in the gas are determined by the equation of dynamics and the balance of enthalpy. Numerical simulation was performed in the OpenFOAM package using the fluid volume method (VOF method) and the standard k-e turbulence model. The evolution of the fields of volumetric gas content, velocity, and pressure during the flow of gas from the high-pressure chamber into a closed channel filled with liquid in the presence of a ”gas blanket“ at the upper end of the channel is obtained. It was shown that the dynamics of pulsations in the gas cavity that occurs when the gas flows into the closed region substantially depends on the physical properties of the liquid in the volume, especially the density. Numerical modeling showed that the injection of gas into water occurs in the form of a jet outflow of gas, and for the outflow into liquid lead, a gas slug is formed at the bottom of the channel. Satisfactory agreement was obtained between the numerical calculation and the calculation according to the asymptotic model for pressure pulsations in a gas projectile in liquid lead. For water, the results of calculations using the asymptotic model give a significant difference from the results of numerical calculations. In all cases, the velocity of the medium obtained by numerical simulation and when using the asymptotic model differ by an order of magnitude or more.

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