Dynamic Characteristics and Stability of Flexible Riser Under Consideration of Non-Uniform Tension and Internal Flow

2021 ◽  
Author(s):  
Dingbang Yan ◽  
Shuangxi Guo ◽  
Yilun Li ◽  
Jixiang Song ◽  
Min Li ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Internal Flow ◽  
Flexible Riser ◽  
Uniform Tension

scholarly journals Dynamic Characteristics and Stability of Flexible Riser Under Consideration of Non-Uniform Tension and Internal Flow

2020 ◽  
Author(s):  
Dingbang Yan ◽  
Shuangxi Guo ◽  
Yilun Li ◽  
Jixiang Song ◽  
Min Li ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Oil And Gas ◽  
Internal Flow ◽  
Oil And Gas Industry ◽  
Travelling Wave ◽  
Flexible Riser ◽  
Modal Shape ◽  
Gas Industry ◽  
Uniform Tension ◽  
The Stability

Abstract As oil and gas industry is developing towards deeper ocean area, the length and flexibility of ocean risers become larger, which may induce larger-amplitude displacement of flexible riser response due to lower structural stiffness against environmental and operational loads. Moreover, suffering not only the external fluid loads coming from environmental ocean wave and current, these risers also convey internal flow. In other words, the dynamic characteristics and response of the flow-conveying riser face great challenge, such as bucking, divergence and flutter, because of the fluid-solid coupling of the internal hydrodynamics and riser structural dynamics. In this study the dynamic characteristics and stability of a flexible riser, under consideration of its internal flow and, particularly, non-uniform axial tension, are examined through our FEM numerical simulations. First, the governing equations and FEM models of a flexible riser with axially-varying tension and internal flow are developed. Then the dynamic characteristics, including the coupled frequency and modal shape, are presented, as considering the speed of internal speed changes. At last, the dynamic response and corresponding stability behaviors are discussed and compared with the cases of riser with uniform tension. Our FEM results show that the stability and response are quite different from riser with uniform tension. And, the time-spatial evolution of riser displacement exhibit a strong wave propagation phenomenon where travelling wave are observed.

scholarly journals J051041 Analysis on Dynamic Characteristics of a Rocket Pump Internal Flow

2011 ◽  
Vol 2011 (0) ◽  
pp. _J051041-1-_J051041-5
Author(s):  
Takashi SHIMURA ◽  
Satoshi KAWASAKI ◽  
Masaharu UCHIUMI ◽  
Mitsuaki HAYASHI ◽  
Jun MATSUI
Keyword(s):  
Dynamic Characteristics ◽  
Internal Flow

An Experimental Analysis of a Flexible Riser in Jumper Configuration

2011 ◽  
Author(s):  
Motohiko Murai ◽  
Marcio Yamamoto ◽  
Shotaro Uto ◽  
Tomo Fujiwara
Keyword(s):  
Deep Sea ◽  
Degrees Of Freedom ◽  
Steel Wire ◽  
Internal Flow ◽  
Flexible Riser ◽  
Hydrocarbon Production ◽  
Positive Displacement ◽  
Production Platform ◽  
Displacement Pump ◽  
Torque Transducer

Nowadays, flexible risers are widely deployed in various configurations for the production of hydrocarbons in offshore fields. For example, in the self-standing hybrid risers’ applications, a single riser or a set of risers are suspended by a subsurface buoy called “Can”. Then a piece of flexible riser connects the Can to the production platform conveying the hydrocarbon production stream. This work concerns about this jumper, an experiment using a 10 m long model was carried out at the Deep Sea Basin of the National Maritime Research Institute in Japan. The model was made by three concentric unbonded layers: a silicon made inner layer; a crisscross steel wire layer; and a rubber made outer layer. During this experiment, the model was suspended through both ends; one model’s end was fixed and the other end was connected to an oscillator that generates the oscillatory motion in three different directions. In addition, a positive displacement pump injected fresh water into the model. Further, the model was instrumented with two degrees of freedom accelerometers fixed along its length; and a six degrees of freedom force/torque transducer was also installed at one pipe end. In addition, the Deep Sea Basin’s Visual Measurement System tracks and calculates the motion of several measurement stations along the pipe. A parametric analysis was carried out changing the oscillating frequency and internal flow rate. Discussion and results of numerical simulation are also included.

J051042 Optimal Design of Internal Flow System in Rocket Pump Considering Dynamic Characteristics

2011 ◽  
Vol 2011 (0) ◽  
pp. _J051042-1-_J051042-5
Author(s):  
Satoshi KAWASAKI ◽  
Takashi SHIMURA ◽  
Masaharu UCHIUMI ◽  
Mitsuaki HAYASHI ◽  
Jun MATSUI
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
Flow System ◽  
Internal Flow

Dynamic Characteristics of Swing Check Valve Based on Dynamic Mesh and UDF

2013 ◽  
Vol 321-324 ◽  
pp. 86-89
Author(s):  
Shu Xun Li ◽  
Ying Zhe Hou ◽  
Lian Cui Li
Keyword(s):  
Dynamic Characteristics ◽  
Working Condition ◽  
Check Valve ◽  
Internal Flow ◽  
Dynamic Mesh ◽  
Motion Model ◽  
Valve Design ◽  
Transient Dynamic Analysis ◽  
Modified Model ◽  
Dynamic Numerical Simulation

In view of the transient dynamic analysis in opening swing check valve, the motion model of valve clack is built, two-dimensional dynamic numerical simulation of the internal unsteady flow is performed by using dynamic mesh and UDF in opening two kinds of swing check valve at the same working condition, the visualized results are obtained. The results show that internal flow field of the modified model become more stable, the noise, impact and the local energy loss are decreased, the service life is improved obviously; an important reference for swing check valve design and analysis of dynamic characteristics are provided by the research results.

Experimental Analysis of Reduced-Scale Jumper for Deep-Sea Mining

2019 ◽  
Author(s):  
Marcio Yamamoto ◽  
Tomo Fujiwara ◽  
Shigeo Kanada ◽  
Masao Ono ◽  
Satoru Takano ◽  
...  
Keyword(s):  
Deep Sea ◽  
Numerical Models ◽  
Oscillation Amplitude ◽  
Internal Flow ◽  
Differential Pressure ◽  
Scale Model ◽  
Pressure Amplitude ◽  
Flexible Riser ◽  
Flexible Pipe ◽  
Reduced Scale

Abstract In the Deep-Sea Mining, the seafloor mining tool is connected to the subsea slurry pump by a piece of flexible pipe named jumper. The jumper’s shape is similar to a steep-wave flexible riser. Compared to a flexible riser, the jumper is a reinforced hose and has a shorter length. Numerous studies shed light on the dynamic behavior of flexible riser; however, all studies were carried out by the way of numerical analysis. We carried out, in the Deep-Sea Basin, an experiment using 1/5 reduced scale model of the jumper. Unhappily, the model’s bending stiffness had to be distorted. During the experiment, an oscillator generated harmonic motion on the top end of the model and a centrifugal pump circulated water throughout the model. In addition, we installed load cells on the top and bottom ends of the model. Our Basin is equipped with a visual measurement system. Thus, we measured the displacement of targets attached to the model. The initial results show that axial tension amplitude increases with the frequency of the top end oscillation. This response is due to the drag force on the lower bend increases with the frequency of top motion. We also could observe that the internal flow may increase the vertical motion amplitude. The jumper’s motion generates an oscillation on the internal differential pressure between both ends and the flow velocity. The differential pressure amplitude increases with the top oscillation frequency, but it is proportional to the top end oscillation amplitude. We will use these experimental results to validate our numerical models. Further, it is important to understand the internal flow effects to design the actual pump used to convey the slurry through the jumper.

Full-Scale Testing of Flexible Riser System Subjected to Internal Flow-Induced Vibration

2006 ◽  
Author(s):  
M.J. Every ◽  
H.G.D. Goyder ◽  
T. Jee ◽  
R. Swindell ◽  
L. Billingham
Keyword(s):  
Internal Flow ◽  
Full Scale ◽  
Flexible Riser ◽  
Flow Induced Vibration ◽  
Full Scale Testing

scholarly journals Dynamic Behavior of Tubes Subjected to Internal and External Cross Flows

1997 ◽  
Vol 4 (2) ◽  
pp. 77-91 ◽  
Author(s):  
Yii-Mei Huang ◽  
Chih-Shan Hsu
Keyword(s):  
Dynamic Characteristics ◽  
Multiple Scales ◽  
Cross Flow ◽  
Internal Flow ◽  
Numerical Approach ◽  
Small Time ◽  
Steady Flows ◽  
Thin Cylindrical Shell ◽  
Pressure Distributions ◽  
The Stability

This article presents a method for thoroughly examining the dynamic characteristics of a tube under the influence of either the internal flow or the external cross flow. The tube is modeled as a thin cylindrical shell whose governing equations are derived from an energy method. The effects due to internal flow are introduced into the system through initial stress. Galerkin’s method in conjunction with the method of multiple scales is employed for obtaining the stability of the tube vibration. According to the results, instability can occur under certain conditions of resonance. Regarding the effects of the external cross flow, a numerical approach is initially employed to interpolate the experimental data of the pressure distributions due to the flow. The dynamic characteristics of the tube under steady flows and flows with small time variation are then investigated. Stability of the solution is also discussed.

Sign in / Sign up

Export Citation Format

Share Document