The Study of a Possible Strengthened Structure Implanting Into the Hoses in Umbilical for Deep Water Application

2016 ◽  
Author(s):  
Chongyao Zhou ◽  
Liang Zhang ◽  
Yongtian Kang ◽  
Yan Qu ◽  
Kevin Huang ◽  
...  
Keyword(s):  
Deep Water ◽  
Steel Tube ◽  
Water Application ◽  
Prior Record ◽  
Duplex Steel ◽  
Control Fluid ◽  
Pressure Resistance ◽  
The Cost ◽  
Resistance Performance ◽  
Depth Water

Umbilical is the key actor connecting the subsea devices on the seabed to the platform, and acting like a neural line transforming the information from the central control system on platform to the subsea control elements. Normally, according to the applied chemical reagent and hydraulics control fluid transmitting element, the umbilical is divided into two types for alternative depths, one consists with hoses for shallow water or medium water application, and the other utilizes the super duplex steel tubes for all depth water application. The main argument for using steel over thermoplastic hoses would be chemical resistance and hydraulic response time (where hose performance is poor). However, the hose will have more flexibility than steel tube, which is also easier for manufacture. If the umbilical with hoses can be used in deeper water condition, the cost will decrease greatly. In order to strengthen the hose structure for deep water use (up to 1000m twice the prior record), this paper will focus on the study of a possible strengthened structure implanting into the hoses to increase the outer pressure resistance capacity, which will increase the whole outer pressure resistance performance of umbilical finally. The thermoplastic hose with strengthened structure will enable the use of thermoplastic hoses in deeper water.

Resistance Tests of an Articulated Pusher Barge System in Deep and Shallow Water

2021 ◽  
Author(s):  
Li Zhang ◽  
Lei Xing ◽  
Mingyu Dong ◽  
Weimin Chen
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Deep Water ◽  
Water Resistance ◽  
Model Tests ◽  
System 2 ◽  
Changing Trend ◽  
The Difference ◽  
Transport Vessel ◽  
Resistance Performance

Abstract Articulated pusher barge vessel is a short-distance transport vessel with good economic performance and practicability, which is widely used in the Yangtze River of China. In this present work, the resistance performance of articulated pusher barge vessel in deep water and shallow water was studied by model tests in the towing tank and basin of Shanghai Ship and Shipping Research Institute. During the experimental investigation, the articulated pusher barge vessel was divided into three parts: the pusher, the barge and the articulated pusher barge system. Firstly, the deep water resistance performance of the articulated pusher barge system, barge and the pusher at design draught T was studied, then the water depth h was adjusted, and the shallow water resistance at h/T = 2.0, 1.5 and 1.2 was tested and studied respectively, and the difference between deep water resistance and shallow water resistance at design draught were compared. The results of model tests and analysis show that: 1) in the study of deep water resistance, the total resistance of the barge was larger than that of the articulated pusher barge system. 2) for the barge, the shallow water resistance increases about 0.4–0.7 times at h/T = 2.0, 0.5–1.1 times at h/T = 1.5, and 0.7–2.3 times at h/T = 1.2. 3) for the pusher, the shallow water resistance increases about 1.0–0.4 times at h/T = 2.7, 1.2–0.9 times at h/T = 2.0, and 1.7–2.4 times at h/T = 1.6. 4) for the articulated pusher barge system, the shallow water resistance increases about 0.2–0.3 times at h/T = 2.0, 0.5–1.3 times at h/T = 1.5, and 1.0–3.5 times at h/T = 1.2. Furthermore, the water depth Froude number Frh in shallow water was compared with the changing trend of resistance in shallow water.

Design and Experimental Research on Deep Water Pressure Resistance System of Argo Float

2019 ◽  
Vol 83 (sp1) ◽  
pp. 116
Author(s):  
Hanling Wu ◽  
Yanjun Liu ◽  
Gang Xue ◽  
Fengxiang Guo ◽  
Zhitong Li ◽  
...  
Keyword(s):  
Experimental Research ◽  
Deep Water ◽  
Water Pressure ◽  
Argo Float ◽  
Resistance System ◽  
Pressure Resistance

Localization Approach of Damage in Welded Joint Based on Acoustic Emission Beamforming

2014 ◽  
Author(s):  
Denghong Xiao ◽  
Tian He ◽  
Xiandong Liu ◽  
Yingchun Shan
Keyword(s):  
Acoustic Emission ◽  
Welded Joints ◽  
Welded Joint ◽  
Steel Tube ◽  
Area Of Interest ◽  
Novel Approach ◽  
Line Array ◽  
The Cost ◽  
Localization Approach ◽  
Ae Signals

A novel approach of locating damage in welded joints is proposed based on acoustic emission (AE) beamforming, which is particularly applicable to complex plate-like structures. First, five AE sensors used to obtain AE signals generated from damage are distributed on the surface of the structure in a uniform line array. Then the beamforming method is adopted to detect the weld joints in the area of interest rather than all the points of the whole structure, and to determine the location and obtain information of AE sources. In order to study the ability of the proposed method more comprehensively, a rectangular steel tube with welded joints is taken for the pencil-lead-broken test. The localization results indicate that the proposed localization approach can effectively localize the failure welded joints. This improvement greatly reduces the cost of computation and also improves the efficiency of localization work compared with the traditional beamforming.

scholarly journals Axial Behavior of Concrete-Filled Double-Skin Tubular Stub Columns Incorporating PVC Pipes

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1434
Author(s):  
Muhammmad Faisal Javed ◽  
Haris Rafiq ◽  
Mohsin Ali Khan ◽  
Fahid Aslam ◽  
Muhammad Ali Musarat ◽  
...  
Keyword(s):  
Steel Tube ◽  
Tube Material ◽  
Steel Tubes ◽  
Tubular Columns ◽  
Axial Capacity ◽  
Double Skin ◽  
Axial Behavior ◽  
Pvc Pipe ◽  
The Cost ◽  
Stub Columns

This experimental study presents concrete-filled double-skin tubular columns and demonstrates their expected advantages. These columns consist of an outer steel tube, an inner steel tube, and concrete sandwiched between two tubes. The influence of the outer-to-inner tube dimension ratio, outer tube to thickness ratio, and type of inner tube material (steel, PVC pipe) on the ultimate axial capacity of concrete-filled double-skin tubular columns is studied. It is found that the yield strength of the inner tube does not significantly affect the ultimate axial capacity of concrete-filled double-skin tubular composites. With the replacement of the inner tube of steel with a PVC pipe, on average, less than 10% strength is reduced, irrespective of size and dimensions of the steel tube. Hence, the cost of a project can be reduced by replacing inner steel tubes with a PVC pipes. Finally, the experimental results are compared with the existing design methods presented in AISC 360-16 (2016), GB51367 (2019), and EC4 (2004). It is found from the comparison that GB51367 (2019) gives better results, followed by AISC (2016) and EC4 (2004).

Tensioned Step Riser Configuration for Ultra-Deep Application

2015 ◽  
Author(s):  
Yuan Tian ◽  
Yucheng Hou ◽  
Fabio Pires ◽  
Zhimin Tan
Keyword(s):  
Deep Water ◽  
Research Study ◽  
Fatigue Analysis ◽  
Fatigue Performance ◽  
Water Application ◽  
Commercial Software ◽  
Environmental Loading ◽  
Field Development ◽  
Water Field ◽  
Strong Candidate

This paper presents and compares the results of a research study for an ultra-deep water field development. A total of three riser configurations were modeled with the commonly used commercial software, and both extreme and fatigue analysis were performed. The advantage of tensioned step riser configuration, a patented and innovative riser configuration specially designed for ultra-deep water application, is demonstrated over other traditional configurations such as free-hanging configuration and double-hump lazy wave configuration. The analysis results indicated that the proposed tensioned step riser configuration has largely favorable features in extreme and fatigue performance for deep water application. The tensioned step riser configuration should be treated as a strong candidate for ultra-deep water flexible developments under substantially harsh environmental loading with worse vessel responses.

Numerical Simulation of Dynamics of a Spar Type Floating Wind Turbine and Comparison With Laboratory Measurements

2016 ◽  
Author(s):  
Hyunseong Min ◽  
Cheng Peng ◽  
Fei Duan ◽  
Zhiqiang Hu ◽  
Jun Zhang
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Numerical Simulations ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Deep Water ◽  
Offshore Wind ◽  
Wind Loads ◽  
Floating Offshore Wind Turbines ◽  
The Cost

Wind turbines are popular for harnessing wind energy. Floating offshore wind turbines (FOWT) installed in relatively deep water may have advantages over their on-land or shallow-water cousins because winds over deep water are usually steadier and stronger. As the size of wind turbines becomes larger and larger for reducing the cost per kilowatt, it could bring installation and operation risks in the deep water due to the lack of track records. Thus, together with laboratory tests, numerical simulations of dynamics of FOWT are desirable to reduce the probability of failure. In this study, COUPLE-FAST was initially employed for the numerical simulations of the OC3-HYWIND, a spar type platform equipped with the 5-MW baseline wind turbine proposed by National Renewable Energy Laboratory (NREL). The model tests were conducted at the Deepwater Offshore Basin in Shanghai Jiao Tong University (SJTU) with a 1:50 Froude scaling [1]. In comparison of the simulation using COUPLE-FAST with the corresponding measurements, it was found that the predicted motions were in general significantly smaller than the related measurements. The main reason is that the wind loads predicted by FAST were well below the related measurements. Large discrepancies are expected because the prototype and laboratory wind loads do not follow Froude number similarity although the wind speed was increased (or decreased) in the tests such that the mean surge wind force matched that predicted by FAST at the nominal wind speed (Froude similarity) in the cases of a land wind turbine [1]. Therefore, an alternative numerical simulation was made by directly inputting the measured wind loads to COUPLE instead of the ones predicted by FAST. The related simulated results are much improved and in satisfactory agreement with the measurements.

Experimental Study on the Influence of other Factors on Compression Resistance Performance of Emulsion Explosives in Deep Water

2014 ◽  
Vol 535 ◽  
pp. 729-733
Author(s):  
Lei Liu ◽  
Qiang Liu ◽  
Li Cheng
Keyword(s):  
Experimental Study ◽  
Water Content ◽  
Deep Water ◽  
Experimental Results ◽  
Paraffin Wax ◽  
Emulsion Explosive ◽  
Emulsion Explosives ◽  
Small Influence ◽  
Resistance Performance ◽  
Compression Resistance

Since oil phase materials, oxidizer, and water are important components of emulsion explosive, their influences on compression resistance performance of emulsion explosives in deep water was studied by using reusable experiment device to simulate the deep charging environment. The experimental results show that with the equivalent content of the oil phase material, the sequence of three oil phase types of emulsion explosives from good to bad in terms of compression resistance performance and explosion performance in deep water are composite wax, composite wax and machine oil, paraffin wax, vaseline and machine oil. With the equivalent content of oxidant, the type of oxidant species has quite small influence on compression resistance performance and explosion property. Within a certain range, water content has small influence on compression resistance performance, and explosion performance increases with the increasement of water content, while it significantly decreases with water content increasing to a certain amount.

Cancellation of Non-Harmonic Waves Using a Cycloidal Turbine

2011 ◽  
Author(s):  
John T. Imamura ◽  
Stefan G. Siegel ◽  
Casey Fagley ◽  
Tom McLaughlin
Keyword(s):  
Deep Water ◽  
Water Waves ◽  
Linear Time ◽  
Harmonic Wave ◽  
Point Vortex ◽  
Harmonic Waves ◽  
Incoming Wave ◽  
Response Characteristics ◽  
Depth Water ◽  
Multi Component System

We computationally investigate the ability of a cycloidal turbine to cancel two-dimensional non-harmonic waves in deep water. A cycloidal turbine employs the same geometry as the well established Cycloidal or Voith-Schneider Propeller. It consists of a shaft and one or more hydrofoils that are attached eccentrically to the main shaft and can be independently adjusted in pitch angle as the cycloidal turbine rotates. We simulate the cycloidal turbine interaction with incoming waves by viewing the turbine as a wave generator superimposed with the incoming flow. The generated waves ideally are 180° out of phase and cancel the incoming wave downstream of the turbine. The upstream wave is very small as generation of single-sided waves is a characteristic of the cycloidal turbine as has been shown in prior work. The superposition of the incoming wave and generated wave is investigated in the far-field and we model the hydrofoil as a point vortex. This model has previously been used to successfully terminate regular deep water waves as well as intermediate depth water waves. We explore the ability of this model to cancel non-harmonic waves. Near complete cancellation is possible for a non-harmonic wave with components designed to match those generated by the cycloidal turbine for specified parameters. Cancellation of a specific wave component of a multi-component system is also shown. Also, step changes in the device operating parameters of circulation strength, rotation rate, and submergence depth are explored to give insight to the cycloidal turbine response characteristics and adaptability to changes in incoming waves. Based on these studies a linear, time-invarient (LTI) model is developed which captures the steady state wave frequency response. Such a model can be used for control development in future efforts to efficiently cancel more complex incoming waves.

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