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

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.

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The Effects of Solid-Liquid Internal Flow on the Dynamic Behavior of a Reduced-Scale Jumper for Deep-Sea Mining

Volume 5: Ocean Space Utilization ◽

10.1115/omae2020-18688 ◽

2020 ◽

Author(s):

Marcio Yamamoto ◽

Tomo Fujiwara ◽

Shigeo Kanada ◽

Masao Ono ◽

Satoru Takano ◽

...

Keyword(s):

Dynamic Behavior ◽

Measurement System ◽

Deep Sea ◽

Forced Oscillation ◽

Internal Flow ◽

Differential Pressure ◽

Scale Model ◽

Flexible Pipe ◽

Visual Measurement ◽

Reduced Scale

Abstract For the exploitation of seafloor massive sulfides, we have investigated the dynamic behavior of the jumper, a piece of flexible pipe that connects the seafloor mining tool to the subsea slurry pump. In this article, we present the results of the experiment using a 1/5 reduced-scale model of the jumper. This experiment was carried out in Deep-Sea Basin. During the experiment, a slurry fluid was conveyed throughout the jumper’s model. In addition, an oscillator generated harmonic motion on the top end of the model. In terms of instrumentation, we installed load cells on the top and bottom ends of the model and a 3D visual measurement system tracked the motion of measurement stations attached to the model. We present the experimental results measured by the 3D visual measurement system, loads cells, and differential pressure gauges in the cases where a vertically forced oscillation is imposed on the top of the jumper. In this experiment, we could observe the effects of slurry on the jumper reduced-scale model. Since the slurry has a larger density than the single liquid phase, the slurry flow changed, as expected, the static shape of the jumper compared to a jumper conveying only water. The vertical top force average and differential pressure average increase with the volume concentration of solid, while their amplitudes increase quadratically with the forced oscillation frequency.

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An Experimental Study of the Interaction Between Pipe Structure and Internal Flow

Volume 3: Pipeline and Riser Technology ◽

10.1115/omae2009-79312 ◽

2009 ◽

Author(s):

Marcio Yamamoto ◽

Motohiko Murai ◽

Katsuya Maeda ◽

Shotaro Uto

Keyword(s):

Gas Flow ◽

Petroleum Industry ◽

Internal Flow ◽

Scale Model ◽

Offshore Platforms ◽

Drilling Mud ◽

Well Drilling ◽

Hydrocarbon Production ◽

Flow Effects ◽

Reduced Scale

Nowadays pipes are widely deployed in the offshore environment especially in the petroleum industry where rigid and flexible pipes are used for well drilling and hydrocarbon production. Whereas during drilling, a mixture of drilling mud, rock cuttings and sometimes gas flows through the drilling riser, during production mono or multiphase (comprising oil, water and gas) flow takes place within the system. However up till now, most of the studies on offshore pipelines and risers have been focused on the pipe structure and its interaction with hydrodynamic forces and offshore platforms. In particular for numerical computation studies and reduced scale model experiments, the pipe is usually modeled as a tensioned beam and sometimes only the internal pressure is taken into account with other effects due to its internal flow being neglected. This paper deals with the interaction between the pipe structure and its internal flow. In order to verify the internal flow effects, an experimental analysis was carried out not using a reduced scale model. In particular, mono-phase fluid flows into the pipe and a parametric analysis using the flow rate was carried out. Discussion about the experimental results and numerical applications is also included.

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Experimental Investigation of the Effects of a Pulsating Internal Flow on the Dynamics of a Submersed U-Shaped Flexible Pipe

Volume 3: Pipeline and Riser Technology ◽

10.1115/omae2012-83069 ◽

2012 ◽

Author(s):

Marcio Yamamoto ◽

Shotaro Uto ◽

Tomo Fujiwara ◽

Motohiko Murai

Keyword(s):

Dynamic Response ◽

Flow Rate ◽

Deep Sea ◽

New Technologies ◽

Fluid Pressure ◽

Internal Flow ◽

Flexible Pipe ◽

Hydrocarbon Production ◽

Petroleum Production ◽

Single Well

In the past of the offshore petroleum production, each riser had conveyed the hydrocarbon production from a single vertical well; the riser’s internal flow rate was relatively low and only the internal fluid pressure was taking into account for the riser analysis. Other internal flow effects, such as internal fluid’s linear moment, and Coriollis effects, were neglected. However, the paradigm for petroleum production in ultra-deepwater is shifting nowadays. New technologies, such as horizontal wells, have increased the production rate from a single well. In addition, a subsea booster system can increase both pressure and flow rate of the riser’s conveyed fluid. Further, the Offshore Mining is rising as a new industry and will demand riser systems to convey, at high flow rates, the mineral ore’s slurry from the seafloor up to the production support vessel. In a previous experiment, the effects of the internal flow on a vertical riser were investigated. In the current experiment, the main objective is to investigate the effect of the internal flow on the dynamic response of a pipe in “jumper configuration”. The experiment was carried out at the Deep Sea Basin of the National Maritime Research Institute using a 10 m long flexible pipe. The actual “jumper” is a piece of flexible riser, in U-shaped configuration, that connects the main structure of “Self-Standing Hybrid Riser” to the production vessel. During the experiment, fresh water was pumped into the model by positive displacement pump; and an oscillator applies a harmonic vibration on one pipe’s end. Then the pipe’s dynamic response is measured by the Deep Sea Basin’s 3D Visual Measurement System. Results for different internal flows and oscillations are compared.

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The Effects of Solid-Liquid Internal Flow on the Dynamic Behavior of a Reduced-Scale Jumper for the Deep-Sea Mining

10.1115/1.0000968v ◽

2021 ◽

Author(s):

Marcio Yamamoto ◽

Tomo Fujiwara ◽

Shigeo Kanada ◽

Masao Ono ◽

Satoru Takano ◽

...

Keyword(s):

Dynamic Behavior ◽

Deep Sea ◽

Internal Flow ◽

Solid Liquid ◽

Reduced Scale

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An Experimental Analysis of a Flexible Riser in Jumper Configuration

Volume 4: Pipeline and Riser Technology ◽

10.1115/omae2011-49506 ◽

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.

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Reduced-Scale Model Tests of Fires in Railway Tunnel and Structure Fire Safety

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.168-170.2473 ◽

2010 ◽

Vol 168-170 ◽

pp. 2473-2476 ◽

Cited By ~ 1

Author(s):

Hong Li Zhao ◽

Zhi Sheng Xu ◽

Xue Peng Jiang

Keyword(s):

Fire Safety ◽

Numerical Models ◽

Scale Model ◽

Railway Tunnel ◽

Tunnel Fires ◽

Tunnel Fire ◽

Longitudinal Ventilation ◽

Overall Stability ◽

Reduced Scale ◽

Ventilation Velocity

The high-temperature toxic gas released by long railway tunnel fires not only causes great harm to persons, but also damages the structure of the tunnel which will reduce the overall stability of tunnel. In order to diminish the damage to tunnel structure produced by a tunnel fire, on the basis of the first extra-long underwater railway tunnel in China, some reduced-scale tests were carried out to study the distribution of smoke temperature along the tunnel ceiling, the smoke velocity and the backlayering distance with the fire size of 63KW. The longitudinal ventilation velocity and the tunnel gradient varied in these tests. The smoke temperature below the tunnel ceiling in different times and under different longitudinal ventilation velocity, the smoke velocity under the ceiling, and the backlayering distance in the presence of different ventilation velocity are acquired from the tests. The conclusions have the guiding meaning to the disaster prevention design and construction of structure fire safety in tunnel fires, and all the experimental data presented in this paper are applicable for the verification of numerical models.

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A Model Experiment of a Free Standing Riser in the Deep-Sea Basin

Volume 4A: Pipeline and Riser Technology ◽

10.1115/omae2013-10577 ◽

2013 ◽

Author(s):

Marcio Yamamoto ◽

Sotaro Masanobu ◽

Satoru Takano ◽

Shigeo Kanada ◽

Tomo Fujiwara ◽

...

Keyword(s):

Deep Sea ◽

Model Experiment ◽

Scale Model ◽

Vertical Pipe ◽

Free Standing ◽

Visual Measurement ◽

Smooth Cylinder ◽

Induced Motion ◽

Reduced Scale ◽

A Current

An experiment using a 1/70 reduced scale model of a Free Standing Riser (FSR) was carried in the Deep-Sea Basin of the National Maritime Research Institute in Japan. For instance, the model’s vertical pipe was about 32m long and the jumper was about 8m long. The FSR model had several measurement stations attached along the vertical pipe, subsurface buoy and jumper; and the motion of each station was measured in 3D by the Visual Measurement System. During the experiment, the effects of the jumper’s top end oscillation on the whole system were investigated. In this case, the top oscillation had propagated along the jumper; however the top oscillation had a reduced effect on the dynamics of the subsurface buoy and vertical pipe. In another experimental case, a current was generated in order to investigate the Vortex Induced Motion (VIM) on the FSR’s Subsurface Buoy. The VIM experiment was repeated for two different buoy models (a smooth cylinder and a cylinder with 3-start heli-coidally strakes) and the results were compared. In this article, some of the experimental results are presented and discussed.

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Nonlinear dynamics of a shell encapsulated microbubble near solid boundary in an ultrasonic field

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.3.2020.23.0568 ◽

2020 ◽

Vol 14 (3) ◽

pp. 7235-7243

Author(s):

N.M. Ali ◽

F. Dzaharudin ◽

E.A. Alias

Keyword(s):

Oscillation Amplitude ◽

Ultrasonic Field ◽

Dynamical Behaviour ◽

Ultrasound Contrast Agents ◽

Chaotic Behaviour ◽

Solid Boundary ◽

Driving Frequency ◽

Pressure Amplitude ◽

Radial Expansion ◽

Therapeutic Delivery

Microbubbles have the potential to be used for diagnostic imaging and therapeutic delivery. However, the transition from microbubbles currently being used as ultrasound contrast agents to achieve its’ potentials in the biomedical field requires more in depth understanding. Of particular importance is the influence of microbubble encapsulation of a microbubble near a vessel wall on the dynamical behaviour as it stabilizes the bubble. However, many bubble studies do not consider shell encapsulation in their studies. In this work, the dynamics of an encapsulated microbubble near a boundary was studied by numerically solving the governing equations for microbubble oscillation. In order to elucidate the effects of a boundary to the non-linear microbubble oscillation the separation distances between microbubble will be varied along with the acoustic driving. The complex nonlinear vibration response was studied in terms of bifurcation diagrams and the maximum radial expansion. It was found that the increase in distance between the boundary and the encapsulated bubble will increase the oscillation amplitude. When the value of pressure amplitude increased the single bubble is more likely to exhibit the chaotic behaviour and maximum radius also increase as the inter wall-bubble distance is gradually increased. While, with higher driving frequency the maximum radial expansion decreases and suppress the chaotic behaviour.

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