scholarly journals Cold Ironing Galvanic Corrosion Issues with Regard to a Shore-to-Ship Medium Voltage Connection

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5372
Author(s):  
Maciej Kozak ◽  
Jarosław Chmiel
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Real World ◽  
Power Supply ◽  
Galvanic Corrosion ◽  
Combustion Engines ◽  
Medium Voltage ◽  
Real World Applications ◽  
Concrete Degradation ◽  
Simulation Results

Cold ironing refers to the usage of less polluting power supply sources to deliver electricity to the moored ship. Such a shore-to-ship system is used when the ship is at a port so the auxiliary combustion engines may be turned off. This paper presents the numerical simulation results of a medium voltage cold-ironing system with regard to the currents flowing between the ship’s hull and grounding busbar. The IT electrical inland system with a neutral grounding resistor, as commonly used in shore-to-ship systems, is investigated. Parasitic capacitances present between the phase-to-hull and phase-to-ground in real-world applications can vary from each other. The direct and alternating currents flowing across the hull, seawater and the pier structure are amongst the causes that can lead to premature reinforced concrete degradation. Chosen cases of phase-to-ground or hull unequal capacitances influencing AC stray currents were considered.

Impact of efficiency and practicality of CFRP anchor installation techniques on the performance of RC beams strengthened with CFRP sheets

2019 ◽  
Vol 46 (9) ◽  
pp. 796-809 ◽  
Author(s):  
Mohammed A. Zaki ◽  
Hayder A. Rasheed
Keyword(s):  
Reinforced Concrete ◽  
Real World ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Application Time ◽  
Flexural Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Real World Applications ◽  
And Performance

Utilizing fiber reinforced polymer (FRP) anchors can enhance the strength and delay the debonding of flexural FRP in strengthened reinforced concrete (RC) beams. In this study, two different techniques are used for applying carbon FRP (CFRP) spike anchors to improve the performance of RC beams strengthened with CFRP sheets. These two techniques are compared with respect to the ease of application, time spent, size of installation team, and performance. The first technique involved applying the CFRP anchors to begin with, then installing CFRP sheets by separating the fibers at the location of anchors. The second technique applied the CFRP sheets first to the beam soffit right after drilling the holes. This was followed by inserting CFRP anchors through the sheets into the prepared holes. The conclusion indicates that the second technique is easier, faster, and more practical in real-world applications. In addition, the use of distributed CFRP anchors increased the flexural capacity of the strengthened beams.

scholarly journals Simulated and Experimental Study of Sediments Sampling Parameters Based on the VOF Method

2020 ◽  
Author(s):  
Shudong He ◽  
YouDuo Peng ◽  
Yongping Jin ◽  
Jian Yan ◽  
Buyan Wan
Keyword(s):  
Numerical Simulation ◽  
Real World ◽  
Dynamic Viscosity ◽  
Vof Method ◽  
Tube Diameter ◽  
Drainage Area ◽  
Sampling Tube ◽  
Simulation Results ◽  
Seabed Sediments ◽  
Penetration Velocity

Abstract Sediments in the seabed hold vital clues to the study of marine geology, microbial communities and history of ocean life, and the remote operated vehicle (ROV) mounted tubular sampling is an important way to obtain sediments. However, sampling in the seabed is a particularly difficult and complicated task due to the difficulty accessing deep water layers. The sampling is affected by the sampler’s structural parameters, operation parameters and the interaction between the sampling tube and sediments, which usually results in low volume and coring rate of sediments obtained. This paper simulated the soft viscous seabed sediments as non-Newtonian Herschel-Bulkley viscoplastic fluids and established a numerical model for the tubular sampling based on the volume of fluid (VOF) method. The influence rules of the sampling tube diameter, drainage area rate, penetration velocity, and sediments dynamic viscosity on coring rate and volume were studied. The results showed that coring volume was negatively correlated with all the parameters except the sampling tube diameter. Furthermore, coring rate decreased with increases in penetration velocity, drainage area rate, and sediments dynamic viscosity. The coring rate first increased and then decreased with increasing of the sampling tube diameter, and the peak value was also influenced by penetration velocity. Then, based on the numerical simulation results, an experimental sampling platform was set up and real-world sampling experiments were conducted. The simulation results tallied with the experimental results, with a maximum absolute error of only 4.6%, which verified that the numerical simulation model accurately reflected real-world sampling. The findings in this paper can provide a theoretical basis for facilitating the optimal design of the geometric structure of the seabed sediments samplers and the parameters in the sampling process.

Numerical Simulation on Ultimate Bearing Capacity of FRP Reinforced Concrete Notched Beams

2010 ◽  
Vol 452-453 ◽  
pp. 337-340
Author(s):  
Pei Xiu Xia ◽  
Guang Ping Zou ◽  
Jie Lu
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Fracture Mechanism ◽  
Failure Modes ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Three Point Bending ◽  
Extreme Load ◽  
Simulation Results

: In this research, some concrete three-point bending specimens (beams) reinforced by FRP are used in numerical simulation to study the influence of the reinforcement on fracture mechanism and the extreme load-bearing capacity of the specimens. The numerical simulation results show the propagation of the crack in concrete is controlled by using FRP. Meanwhile the load-bearing capacity is increased greatly and failure modes are changed.

scholarly journals Study on equivalent static method for the analysis of fatigue behavior of reinforced concrete beam

2021 ◽  
Vol 272 ◽  
pp. 02018
Author(s):  
Fangping Liu ◽  
Chen Yu ◽  
Wentao Yi
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Static Load ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beam ◽  
Static Method ◽  
Reinforced Concrete Beams ◽  
Simulation Results

In order to analyze the whole process of fatigue behaviours of reinforced concrete beams, an equivalent static analysis method is proposed in this paper. Firstly, the constitutive models based on the degradation of stiffness and strength and the accumulation of residual strain of concrete and reinforcement subjected to fatigue loadings are deduced and established by coupling the uniaxial constitutive model of concrete and the ideal elastic-plastic model of reinforcement under static load. Secondly, based on the similarity of concrete failure under static load and fatigue load, the equivalent relationship between fatigue and static analysis can be constructed by using the concrete residual strain as the equivalent parameter. On this basis, an equivalent static method for the analysis of fatigue behavior of reinforced concrete beam is proposed. At last, three reinforced concrete beams with rectangular section are tested, and the fatigue behaviours are analyzed by the method proposed in this paper. The numerical simulation results are compared with the field test data. The result shows that the numerical simulation results are in good agreement with the experimental results, which verifies the reliability and practicability of the method.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

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