Study of Critical Speed for a Flexible Drill String System Based on Fluid–Structure Interaction

2011 ◽  
Vol 105-107 ◽  
pp. 545-552
Author(s):  
Gui Jie Yu ◽  
Lei Fu ◽  
You Cai Yin
Keyword(s):  
Natural Frequency ◽  
Critical Speed ◽  
Fluid Structure Interaction ◽  
Drill String ◽  
Economic Returns ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Practical Engineering ◽  
Hoisting System ◽  
Multi Body

The TDS changed the drive mode and established a simple, flexible multi-body drill string system. The system consists of a derrick, a hoisting system, TDS, and a drill string system, and is inserted into a long, narrow borehole. The drill string then interacts with mud, the borehole wall, and the bottom hole, which generates resonance and increases the risk of drilling accidents. Natural frequency, which is related to the structure of the drill string, determines critical speed. In a vertical well, the transverse, torsional, and longitudinal fluid–structure interaction vibrations of the flexible multi-body drill string system within 1,700 m was analysed using the ANSYS. The natural frequency and the associated critical speed for different bottomhole assemblies (BHAs) were obtained. Results show that reasonably selecting the TDS rotation speed and optimizing BHA offer practical engineering applications for increasing drilling speed, reducing drilling accidents, and improving economic returns.

Nonlinear Vibrations in a Parametrically Excited Fluid-Structure Interaction System With One-to-One Internal Resonance

2003 ◽  
Author(s):  
Takashi Ikeda
Keyword(s):  
Natural Frequency ◽  
Internal Resonance ◽  
Fluid Structure Interaction ◽  
Liquid Sloshing ◽  
Fluid Structure ◽  
Inertia Effects ◽  
Structure Interaction ◽  
Interaction System ◽  
Resonance Curves ◽  
One To One

Theoretical resonance curves prove that a structure’s resonance can facilitate liquid sloshing even when the internal resonance ratio is one-to-one. An investigation of nonlinear sloshing liquid vibrations in a rectangular tank supported by an elastic structure that is subjected to a vertical and sinusoidal excitation reveals that liquid sloshing occurs when the structure’s natural frequency is approximately equal to the natural frequency of sloshing, that is, in the state of one-to-one internal resonance, and that amplitude-modulated motions appear when the condition of the internal resonance deviates to some extent. A special consideration of the nonlinear inertia effects of liquid force and the use of Galerkin’s method help derive the differential (modal) equations governing the dynamic behaviors of the fluid-structure interaction system, while van der Pol’s method helps express the theoretical resonance curves. These theoretical results are in quantitative agreement with the experimental data.

Coupling Model Analysis on Fluid Structure Interaction in Lifting Pipeling Based on ADINA

2012 ◽  
Vol 468-471 ◽  
pp. 238-244
Author(s):  
Zhao Wang ◽  
Zhi Jin Zhou ◽  
Hao Lu ◽  
Ze Jun Wen ◽  
Yi Min Xia
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Volume Concentration ◽  
Natural Frequencies ◽  
Fluid Structure Interaction ◽  
Element Model ◽  
Structure Design ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Finite Element Software

Using finite element software ADINA, three coupling models on fluid-structure interaction among internal fluid—pipe—external fluid in the lifting pipeline were researched. Firstly, coupling finite element model on fluid structure interaction of lifting pipeline was established and the first sixth order natural frequencies and principal vibration modes were attained at different ore conveying volume concentration and cross-section size of pipeline;Then natural frequencies of three couplings were compared with two couplings and no coupling according to the above condition, and FSI effect on natural frequency of pipeline was discussed. The calculation results were shown that the natural frequency of the pipe and its relative error reduced with the volume concentration and the relative wall thickness increased, which explain the reason that has better accuracy considering three couplings than other .These results have certain directive significance on the dynamic response, structure design and study of reduction vibration of lifting pipeline.

A Hybrid Model to Analyze the Fluid-Structure Interaction Phenomenon of a Relief System and Experimental Validation

2019 ◽  
Author(s):  
Feng Jie Zheng ◽  
Fu Zheng Qu ◽  
Xue Guan Song
Keyword(s):  
Hybrid Model ◽  
Pressure Fluctuation ◽  
Fluid Structure Interaction ◽  
Relief Valve ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Model Combining ◽  
Valve Motion ◽  
Practical Engineering ◽  
Cfd Method

Abstract As one essential component of a pressurized system, a relief valve is used to guarantee the pressure within a prescribed range. But in practical engineering, pressure fluctuation caused by the operation of a relief valve will travel along the pipeline and couple with the motion of the valve, which might result in malfunction of the valve and the system. In order to investigate the fluid-structure interaction (FSI) phenomenon, a hybrid model combining the method of characteristics (MOC) and computational fluid dynamics (CFD) method is proposed. In the hybrid FSI model, the characteristics of pressure resource is modeled using the performance curves, the compressible gas transmitting in the pipe is calculated by one-dimensional MOC, and the air flow in the valve as well as the valve motion is simulated by a two-dimensional CFD model. To validate the hybrid model, 1:1 scaled test rig is conducted. The compared results show that the hybrid model not only can accurately capture the pressure fluctuation in straight pipeline induced by the closure of the valve but also can accurately predict the forms of the valve motion.

Nonlinear Behaviors of Three Dimensional Sloshing in the LNG Elastic Tank

2021 ◽  
Author(s):  
Zhongchang Wang ◽  
Meirong Jiang ◽  
Yang Yu
Keyword(s):  
Natural Frequency ◽  
High Frequency ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Surface Elevation ◽  
Fluid Structure ◽  
Elastic Case ◽  
Structure Interaction ◽  
Elastic Tank ◽  
Sloshing Pressure

Abstract Aiming at the nonlinear sloshing in the LNG tank, a three-dimensional elastic model is established to investigate the fluid structure interaction effect. For the transient flow and the tank motion, the direct coupling method is employed to calculate the interaction between the sloshing and the bulkhead. The finite element software ADINA is adopted to do the computation. The sloshing natural frequency is verified with the results of the theoretical formula. Different wall thicknesses, filling ratios and external excitations are considered and the structure natural frequency, surface elevation and sloshing pressure are obtained. The results of the elastic case are further compared with the rigid results and the nonlinear characteristics are extracted to see the hydro-elastic effect. The sloshing natural frequencies are agreed well with the theoretical results. Due to the influence of the fluid structure interaction, the couple frequencies are obviously less than those of the empty tank. With the increase of the wall thickness, the frequencies of the empty tank and the couple frequencies all increase gradually. For the surface elevation, the thinner the bulkhead thickness is, the more the high frequency component is. The free surface is relatively flat and stable in the rigid tank but tend to be chaotic for the elastic one. Due to the fluid structure interaction, the sloshing pressure of the elastic case presents obvious high-frequency fluctuation and the sloshing pressure in the elastic tank is smaller than that in the rigid tank. This model clearly shows the valuable ability to solve the three dimensional sloshing in the elastic tank.

Numerical Method to Estimate Fluid-Structure Interaction Effect of Ships Under Severe Wave Condition

2018 ◽  
Author(s):  
Tomoki Takami ◽  
Kazuhiro Iijima
Keyword(s):  
Natural Frequency ◽  
Interaction Effect ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Vertical Vibration ◽  
Coupling Method ◽  
Wave Condition ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction

In this study, for the sake of evaluating the structural response taking account of the fluid-structure interaction effect of a ship under severe wave condition, a method for coupling the CFD and 3D FEA in a sequentially staggered manner, is developed. The elastic deformation of the ship is taken over, not only to the following FEA stages but also to the following CFD stages. In order to validate the developed two-way coupling method, and to investigate into the fluid-structure interaction effect on the ship, the comparisons among the straightforward (one-way) coupling method, the experimental results and the developed two-way coupling method are carried out, in terms of the wave-induced loads exerted on the ship, and the hydroelastic response. Both the weakly and strongly coupled methods are investigated. The fluid-structure interaction effect is found as a decrease of the natural frequency of vertical vibration mode of the ship; the natural frequency predicted from the developed two-way coupling method is slightly lower than that from the one-way coupling method.

Fully Coupled Fluid-Structure Interaction for Offshore Applications

2009 ◽  
Author(s):  
Rajeev K. Jaiman ◽  
Farzin Shakib ◽  
Owen H. Oakley ◽  
Yiannis Constantinides
Keyword(s):  
Mass Density ◽  
Fluid Structure Interaction ◽  
Stability And Convergence ◽  
Iterative Coupling ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Vortex Induced Vibrations ◽  
Low Mass ◽  
Density Ratios ◽  
Multi Body

CAD integrated tools are accelerating product development by incorporating various aspects of physics through coupling with computational aided engineering (CAE) packages. One of the most challenging areas is fluid-structure interaction (FSI) of low mass bodies such as flexible marine risers/cables with vortex-induced vibrations. The focus of this work is on the application of a new Multi-Iterative Coupling (MIC) procedure to couple AcuSolve (fluid solver) with Abaqus (structural solver). The proposed new scheme has superior stability and convergence properties as compared to conventional explicit staggered schemes, especially for low mass-density ratios of structure to fluid. Demonstrations and validation of the scheme are presented and discussed along with additional challenges associated with FSI in production environments. The addition of an FEA solver enables the modeling of the nonlinear aspects of flexible riser VIV, namely, contacts with gaps, multi-body dynamics, seabed interaction, geometric and/or material nonlinearities.

scholarly journals Fluid–structure interaction and multi-body contact: Application to aortic valves

2009 ◽  
Vol 198 (45-46) ◽  
pp. 3603-3612 ◽  
Author(s):  
Matteo Astorino ◽  
Jean-Frédéric Gerbeau ◽  
Olivier Pantz ◽  
Karim-Frédéric Traoré
Keyword(s):  
Fluid Structure Interaction ◽  
Aortic Valves ◽  
Fluid Structure ◽  
Body Contact ◽  
Structure Interaction ◽  
Multi Body

Wing Flutter Analysis Using Computational Fluid-Structure Interaction Dynamics

2021 ◽  
Author(s):  
Jeremy A. Pohly ◽  
Mike R. Zhang ◽  
Sijun Zhang
Keyword(s):  
Critical Speed ◽  
Fluid Structure Interaction ◽  
Computational Method ◽  
Fluid Structure ◽  
Aircraft Wings ◽  
Structure Interaction ◽  
Wing Flutter ◽  
Interaction Dynamics ◽  
Lifting Surfaces

Abstract Wing flutter plays a significant role in the performance and life of lifting surfaces such as aircraft wings. It is an instability that causes the wing to no longer be capable of damping out random vibration, and it occurs at the point called the critical speed. Currently, the determination of this critical speed poses a large challenge for aircraft designers, as there is no method that can quickly calculate the conditions that will cause the wing flutter instability. This paper presents wing flutter analyses using computational fluid-structure interaction dynamics. The computed results reveal the potential speed and accuracy of the computational method, which will allow designers to rapidly determine whether their vehicle will be capable of operating safely within its design envelope.

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