The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Fanshun Meng - One of the best experts on this subject based on the ideXlab platform.
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stress analysis of top Tensioned Riser under random waves and vessel motions
Journal of Ocean University of China, 2010Co-Authors: Xiao Min Li, Fanshun MengAbstract:The bending stresses of top Tensioned Riser (TTR) under combined excitations of currents, random waves and vessel motions are presented in this paper, and the effect of the internal flowing fluid on the Riser stresses is also considered. The computation programs which are used to solve the differential equations in the time domain are compiled and the principal factors of concern including the angular movements at the upper and lower ends of the Riser, lateral displacements and bending stresses are presented. Then the effects of current velocity, random wave, top tension, vessel mean offset, low frequency motion and internal flow velocity on the bending stresses of the Riser are analyzed in detail.
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experimental investigation of vortex induced vibration responses of tension Riser transporting fluid
ASME 2009 28th International Conference on Ocean Offshore and Arctic Engineering, 2009Co-Authors: Yongbo Zhang, Fanshun MengAbstract:This paper presents the test results of a vertically Tensioned Riser model under vortex-induced vibrations. The influence of internal flowing fluid and top tensions on the Riser behavior is investigated. Twelve strain gauges were mounted on the Riser and both the in-line and cross-flow responses at locations were measured. The frequency spectrum and amplitude response were derived from the strain date. The influences of internal flow and top tensions on two kinds of model Risers are analyzed and some conclusions are drawn.Copyright © 2009 by ASME
Ricardo Zuccolo - One of the best experts on this subject based on the ideXlab platform.
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top Tensioned Riser system design for the fhsb dry tree semisubmersible platforms
ASME 2013 32nd International Conference on Ocean Offshore and Arctic Engineering, 2013Co-Authors: Jim Yu, Alaa M Mansour, Alan Yu, Ricardo ZuccoloAbstract:The dry tree production and drilling Top Tensioned Riser (TTR) systems have been extensively used with Tension Leg Platforms (TLPs) and Spar floaters in deepwater applications. However, the large heave response of the conventional Semisubmersible floaters makes this type of platforms not suitable for dry tree applications largely due to the ultra-long stroke tensioner that would be required in this case.The Free Hanging Solid Ballast (FHSB) Semi is an innovative new semisubmersible design that is suitable for dry tree applications due to its low heave response that is comparable to that offered by Spar floaters. The new design resembles the conventional Semisubmersibles with an added free-hanging solid ballast tank placed deep below the keel of the Semisubmersible hull and connected to the hull through four groups of chains. The Solid Ballast Tank (SBT) acts as a motion damper that significantly improves the heave motion response.In this paper, the design of the dry tree TTR system for the FHSB Semi is presented. The typical GoM’s drilling and production conditions are used in designing the TTR system including the tensioning system and the interface between the SBT and the Riser keel joint. The feasibility and performance of the designed TTR system are demonstrated through static and dynamic TTR analyses.Copyright © 2013 by ASME
Yongbo Zhang - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of vortex induced vibration responses of tension Riser transporting fluid
ASME 2009 28th International Conference on Ocean Offshore and Arctic Engineering, 2009Co-Authors: Yongbo Zhang, Fanshun MengAbstract:This paper presents the test results of a vertically Tensioned Riser model under vortex-induced vibrations. The influence of internal flowing fluid and top tensions on the Riser behavior is investigated. Twelve strain gauges were mounted on the Riser and both the in-line and cross-flow responses at locations were measured. The frequency spectrum and amplitude response were derived from the strain date. The influences of internal flow and top tensions on two kinds of model Risers are analyzed and some conclusions are drawn.Copyright © 2009 by ASME
Jim Yu - One of the best experts on this subject based on the ideXlab platform.
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top Tensioned Riser system design for the fhsb dry tree semisubmersible platforms
ASME 2013 32nd International Conference on Ocean Offshore and Arctic Engineering, 2013Co-Authors: Jim Yu, Alaa M Mansour, Alan Yu, Ricardo ZuccoloAbstract:The dry tree production and drilling Top Tensioned Riser (TTR) systems have been extensively used with Tension Leg Platforms (TLPs) and Spar floaters in deepwater applications. However, the large heave response of the conventional Semisubmersible floaters makes this type of platforms not suitable for dry tree applications largely due to the ultra-long stroke tensioner that would be required in this case.The Free Hanging Solid Ballast (FHSB) Semi is an innovative new semisubmersible design that is suitable for dry tree applications due to its low heave response that is comparable to that offered by Spar floaters. The new design resembles the conventional Semisubmersibles with an added free-hanging solid ballast tank placed deep below the keel of the Semisubmersible hull and connected to the hull through four groups of chains. The Solid Ballast Tank (SBT) acts as a motion damper that significantly improves the heave motion response.In this paper, the design of the dry tree TTR system for the FHSB Semi is presented. The typical GoM’s drilling and production conditions are used in designing the TTR system including the tensioning system and the interface between the SBT and the Riser keel joint. The feasibility and performance of the designed TTR system are demonstrated through static and dynamic TTR analyses.Copyright © 2013 by ASME
Xiao Min Li - One of the best experts on this subject based on the ideXlab platform.
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dynamic responses of top Tensioned Riser under combined excitation of internal solitary wave surface wave and vessel motion
Journal of Ocean University of China, 2013Co-Authors: Li Zhang, Xiao Min LiAbstract:An investigation on the dynamic response of a top Tensioned Riser (TTR) under combined excitation of internal solitary wave, surface wave and vessel motion is presented in this paper. The Riser is idealized as a Tensioned slender beam with dynamic boundary conditions. The KdV-mKdV equation is chosen to simulate the internal solitary wave, and the vessel motion is analysed by using the method proposed by Sexton. Using finite element method, the governing equation is solved in time domain with Newmark-β method. The computation programs for solving the differential equations in time domain are compiled and numerical results are obtained, including dimensionless displacement and stress. The action of internal solitary wave on the Riser is like a slow powerful impact, and is much larger than those of surface wave and vessel motion. When the Riser is under combined excitation, it vibrates at frequencies of both surface wave and vessel motion, and the vibration is dominated by internal solitary wave. As the internal solitary wave crest passes by the centre of the Riser, the maximum displacement and stress along the Riser occur. Compared to the lower part, the displacement and stress of the Riser in the upper part are much larger.
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combination of random waves and vessel motions effects on the fatigue damage of top Tensioned Riser
Applied Mechanics and Materials, 2011Co-Authors: Xiao Min Li, Peng LiAbstract:As one of the main configurations of the Riser, top Tensioned Riser(TTR) encounters harsh environment in its whole service life. In order to ensure that the Riser will fulfil its intended functions, a fatigue assessment should be carried out for each representative Riser, which is subjected to dynamic fatigue loading. The fatigue life of TTR under the combination excitation of random waves, current and vessel motion is analyzed in this paper. The long-term stress histories of the Riser are calculated and the mean stresses, the number of stress cycles and amplitudes are determined by rain flow counting method. The Palmgren-Miner rule for cumulative damage theory with a specified S–N curve is used to estimate the fatigue life of the Riser. The corresponding numerical programs which can be used to calculate the response and fatigue life of the Riser are compiled. The significant influences of internal flow velocities and low frequency motion of the vessel are analyzed in detail.
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stress analysis of top Tensioned Riser under random waves and vessel motions
Journal of Ocean University of China, 2010Co-Authors: Xiao Min Li, Fanshun MengAbstract:The bending stresses of top Tensioned Riser (TTR) under combined excitations of currents, random waves and vessel motions are presented in this paper, and the effect of the internal flowing fluid on the Riser stresses is also considered. The computation programs which are used to solve the differential equations in the time domain are compiled and the principal factors of concern including the angular movements at the upper and lower ends of the Riser, lateral displacements and bending stresses are presented. Then the effects of current velocity, random wave, top tension, vessel mean offset, low frequency motion and internal flow velocity on the bending stresses of the Riser are analyzed in detail.
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numerical prediction of vortex induced vibrations on top Tensioned Riser in consideration of internal flow
China Ocean Engineering, 2008Co-Authors: Xiao Min LiAbstract:In consideration of the effect of the internal flowing fluid and the external marine environmental condition on the vortex-induced vibration (VIV) of top Tensioned Riser (TIR), the differential equation is derived based on work-energy principles and the Riser near wake dynamics is modeled by Facchinetti's wake oscillator model. Then Galerkin's finite element approximation is implemented to derive the nonlinear matrix equation of the coupled equations and the corresponding numerical programs are compiled which solve the coupled equations directly in the time domain. The comparison of the predicted results with the recent experimental results and the prediction of SHEAR7 is performed. The results show the validity of the proposed method on the prediction of VIV of deep water Risers. The effect of internal flow on the dynamic characteristics and dynamic response of the Riser is analyzed and several valuable conclusions are drawn.
