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Interfacial friction effects on sealing performances of elastomer packer

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Petroleum Science 2024年第3期21卷 2037-2047页

作者： Peng-Cheng Wang Ming-Hui Chen Jim Jenkinson Yong-Xin Song Li Sun department of Mechanical engineering University of HoustonHoustonTX77024USA Guren Nanomaterials Suzhou215127JiangsuChina department of marine engineering Dalian Maritime UniversityDalian116026LiaoningChina

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic *** practice sealing performances of such plugs are normally evaluated through pressure tests,and in numerical simulation studies,maximum contact stress,average contact stress and contact length data are used to determine sealing quality between a packer and *** previous studies,the impact of friction forces on sealing performance is often *** work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing *** first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac *** we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution,deformation,and contact stress after *** the demonstration of validity of FEA method,we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress,average contact stress,contact stress distribution,and maximum mises stress for an actual packer used in plug *** addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial *** study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces.

关键词： Elastomer seal Friction Sealing performance Contact stress

Highly adaptive and broadband triboelectric energy harvester with stretching silicone rubber strip for variable harmonic frequency vibration

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Nano Research 2024年第5期17卷 4089-4099页

作者： Taili Du Dianlong Shen Ziyue Xi Hongyong Yu Fangyang Dong Cong Zhao Meixian Zhu Yongjiu Zou Peiting Sun Minyi Xu Dalian Key Laboratory of marine Micro/Nano Energy and Self-powered Systems Marine Engineering CollegeDalian Maritime UniversityDalian 116026China Collaborative Innovation Research Institute of Autonomous Ship Dalian Maritime UniversityDalian 116026China

An enormous number of wireless sensing nodes(WSNs)are of great significance for the Internet of Things(IoT).It is tremendously prospective to realize the in-situ power supply of WSNs by harvesting unutilized mechanical vibration energy.A harmonic silicone rubber triboelectric nanogenerator(HSR-TENG)is developed focusing on ubiquitous constant working frequency *** unique design of the strip serving as a flexible resonator realizes both soft contact and high and broadband *** significant factors influencing the 1^(st)-order vibration mode of the strip are developed for realizing the harmonic frequency adaptation to external *** surface treatment of the strip improves the output performance of HSR-TENG by 49.1%as well as eliminates the adhesion *** HSR-TENG is able to achieve a voltage output bandwidth of 19 Hz under a vibration strength of 3.0,showing its broadband *** peak power density of 153.9 W/m^(3)is achieved and 12×0.5 W light-emitting diodes(LEDs)are successfully illuminated by the *** can continuously power a temperature sensor by harvesting the actual compressor vibration *** brief,the HSR-TENG provides a promising way for constant frequency vibration energy harvesting,so as to achieve in-situ power supply for the WSNs in the vicinity.

关键词： vibration energy harvesting triboelectric nanogenerator flexible silicone rubber strip harmonic vibration broadband

Experimental study on the dynamic response of a 3-D wedge under asymmetric impact

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Journal of Hydrodynamics 2024年第2期36卷 263-274页

作者： Saeed Hosseinzadeh Kristjan Tabri maritime engineering Research Group School of EngineeringUniversity of SouthamptonSouthamptonUK department of Civil engineering and Architecture Tallinn University of TechnologyTallinnEstonia marine Technology Competence Center Tallinn University of TechnologyKuressaareEstonia

Water entry problems represent complex multiphase flows involving air,water,and structure interaction,occurring rapidly in rough seas,and potentially effecting structural integrity of floating *** paper experimentally investigates asymmetric slamming loads acting on a 3-D elastic wedge *** specimen,featuring two different bottom plates(stiffened and unstiffened),each 4 mm thick,aims to assess the effect of structural stiffness on dynamic *** experiments are conducted at different drop heights of 25 cm and 50 cm and varying heel angles from 5°to 25°.The paper describes the experimental conditions,including wedge geometry,material properties,and the test *** study explores the influence of heel angle on impact acceleration,revealing an increase in peak acceleration with a higher inclination angle,particularly in the vertical ***,the hydrodynamic pressure resulting from asymmetric slamming is *** pressure results analyzed and compared at different locations along the length of the *** experimental findings indicate that,despite the leeward side(stiffened)experiencing a smaller hydrodynamic load,the heel angle significantly affects pressure results on the windward side(unstiffened),leading to a more pronounced dynamic *** time history of pressure results emphasizes the effect of elastic vibrations,particularly noticeable on the unstiffened bottom *** study contributes to a deeper understanding of asymmetric slamming on aluminum structures,facilitating the enhancement of mathematical models and the validation of numerical simulations.

关键词： Flexible fluid structure interactions(FFSI) experimental study asymmetric impact hydrodynamic pressure slamming loads

Finite element model updating for structural damage detection using transmissibility data

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Earthquake engineering and engineering Vibration 2024年第1期23卷 87-101页

作者： Ahmad Izadi Akbar Esfandiari department of maritime engineering Amirkabir University of TechnologyTehran 15875-4413Iran

This paper presents a new finite element model updating method for estimating structural parameters and detecting structural damage location and severity based on the structural responses(output-only data).The method uses the sensitivity relation of transmissibility data through a least-squares algorithm and appropriate normalization of the extracted *** proposed transmissibility-based sensitivity equation produces a more significant number of equations than the sensitivity equations based on the frequency response function(FRF),which can estimate the structural parameters with higher *** abilities of the proposed method are assessed by using numerical data of a two-story two-bay frame model and a plate structure *** evaluating different damage cases,the number,location,and stiffness reduction of the damaged elements and the severity of the simulated damage have been accurately *** reliability and stability of the presented method against measurement and modeling errors are examined using error-contaminated *** parameter estimation results prove the method’s capabilities as an accurate model updating algorithm.

关键词： damage detection model updating output-only transmissibility sensitivity equation

Numerical Analysis of the Influence of the Impinging Distance on the Scouring Efficiency of Submerged Jets

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Fluid Dynamics & Materials Processing 2024年第2期20卷 429-445页

作者： Hao Chen Xianbin Teng Zhibin Zhang Faxin Zhu Jie Wang Zhaohao Zhang School of Naval Architecture and maritime Zhejiang Ocean UniversityZhoushan316022China School of marine engineering Guangzhou Maritime UniversityGuangzhou510725China

Water jet technology is widely used in submerged buried pipes as a non-traditional trenching process,often invol-ving a complex sediment *** important adjustable and inﬂuential engineering variable in this technol-ogy is represented by the impinging *** this study,the FLOW-3D software was used to simulate the jet scouring of sand beds in a submerged *** particular,four sets of experimental conditions were con-sidered to discern the relationship between the maximum scour depth and mass and the impinging *** shown by the results,a critical impinging distance h0 exists by which the static scour depth can be maximized;the scour mass ratio between dynamic and static conditions decreases as the impinging distance ***,the proﬁle contours are similar when the erosion parameter Ec is in the range 0.35

关键词： Submerged jet impinging distance numerical simulation scour depth scour proﬁle

Assessing Dietary Consumption of Sodium and Potassium in China through Wastewater Analysis

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Biomedical and Environmental Sciences 2024年第1期37卷 127-131页

作者： TAN Dong Qin LIANG Yi GUO Ting LI Yan Ying SONG Yong Xin WANG De Gao College of Environmental Science and engineering Dalian Maritime UniversityDalian 116026LiaoningChina College of marine engineering Dalian Maritime UniversityDalian 116026LiaoningChina

A causal relationship has been reported between the average population salt(sodium chloride)intake and the increased risk of stroke and cardiovascular and cerebrovascular diseases in some epidemiological and clinical *** World Health Organization has recommended that a sodium intake of<2 g/day is preventive against cardiovascular disease,although the current intake is in excess in most countries.

关键词： Wastewater intake Potassium

Highly adaptive triboelectric tactile sensor on the foot of autonomous wall-climbing robots for detecting the adhesion state and avoiding the hazard

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Nano Research 2024年第7期17卷 6518-6526页

作者： Zhaoyang Wang Jianhua Liu Ziyu Wang Chang Liu Qingyu Chen Chaofan Zhang Wenbo Zhang Jicang Si Xiu Xiao Peng Xu Minyi Xu Dalian Key Lab of marine Micro/Nano Energy and Self-powered System Marine Engineering CollegeDalian Maritime UniversityDalian 116026China Information Science and Technology College Dalian Maritime UniversityDalian 116026China Navigation College Dalian Maritime UniversityDalian 116026China Intelligent Biomimetic Design Lab College of EngineeringPeking UniversityBeijing 100871China

Due to the excellent maneuverability and obstacle crossing of legged robots,it is possible for an autonomous legged wallclimbing robots to replace manual inspection of ship exterior ***,when the magnetic adsorption legged wallclimbing robot steps on the convex point or convex line of the wall,or even when the robot missteps,the robot is likely to detach from the ferromagnetic ***,this paper proposes a tactile sensor for the legged magnetic adsorption wall-climbing robot to detect the magnetic adsorption state and improve the safety of the autonomous crawling of the *** tactile sensor mainly comprises a three-dimensional(3D)-printed shell,a tactile slider,and three isometric sensing units,with an optimized *** experiment shows that the triboelectric tactile sensor can monitor the sliding depth of the tactile slider and control the light-emitting device(LED)signal *** addition,in the demonstration experiment of detecting the adsorption state of the robot's foot,the triboelectric tactile sensor has strong adaptability to various ferromagnetic wall ***,this study establishes a robot gait control system to verify the feedback control ability of the triboelectric tactile *** results show that the robot equipped with the triboelectric tactile sensor can recognize the dangerous area on the crawling wall and autonomously avoid the ***,the proposed triboelectric tactile sensor has great potential in realizing the tactile sensing ability of robots and enhancing the safety and intelligent inspection of ultra-large vessels.

关键词： legged wall-climbing robot ship inspection tactile perception triboelectric sensor

Experimental and Three-Dimensional Numerical Simulation of Phenomena Induced by Submerged Oblique Jet Scouring

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1799-1821页

作者： Hao Chen Xianbin Teng Faxin Zhu Zhibin Zhang Jie Wang School of Naval Architecture and maritime Zhejiang Ocean UniversityZhoushan316022China School of marine engineering Guangzhou Maritime UniversityGuangzhou510725China

Scouring experiments were conducted using a three-dimensional laser scanning technology for angles of the jet spanning the interval from 0°to 30°,and the characteristics of the scour hole in equilibrium conditions were investigated *** results indicate that the optimal scouring effects occur when the jet angle is in the ranges between 15°and 20°.Moreover,the dimensionless profiles of the scour hole exhibit a high degree of similarity at different jet *** simulations conducted using the Flow-3D software to investigate the bed shear stress along the jet impingement surface have shown that this stress is influenced by both the resultant force and the jet impingement surface *** reaches its maximum value when the jet is vertical,decreases rapidly as the jet starts to tilt,then increases slightly,and decreases again significantly when the angle exceeds 20°.

关键词： Submerged jet jet angle experimental study numerical simulation bed shear stress

Long Duration Coverage Control of Multiple Robotic Surface Vehicles Under Battery Energy Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1695-1698页

作者： Shengnan Gao Zhouhua Peng Haoliang Wang Lu Liu Dan Wang the School of Electrical and Control engineering North China University of TechnologyBeijing 100144 the School of marine Electrical engineering Dalian Maritime UniversityDalian 116026China State Key Laboratory of maritime Technology and Safety Dalian 116026 Dalian Key Laboratory of Swarm Control and Electrical Technology for Intelligent Ships Dalian 116026 the School of marine engineering Dalian Maritime UniversityDalian 116026

Dear Editor,This letter addresses long duration coverage problem of multiple robotic surface vehicles(RSVs) subject to battery energy constraints,in addition to uncertainties and disturbances. An anti-disturbance energy-aware control method is proposed for performing coverage task of RSVs. Firstly, a centroidal Voronoi tessellation(CVT) is used to optimize the partition of the given coverage area.

关键词： Robotic Battery partition