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Full-Text Articles in Engineering

Approach To Problem Solving And Use Of Intuition By Engineering Technology Students, Meher R. Taleyarkhan, Anne M. Lucietto, Natalie L. F. Hobson, Therese M. Azevedo Mar 2023

Approach To Problem Solving And Use Of Intuition By Engineering Technology Students, Meher R. Taleyarkhan, Anne M. Lucietto, Natalie L. F. Hobson, Therese M. Azevedo

Journal of Global Education and Research

Engineering technology students often forgo a methodical approach of solving or answering questions on assignments or exams in favor of an intuition-based approach, emphasizing educated guessing (Broberg et al., 2008). Faculty observations have noted these student solutions often provide explanations, usually sans calculations, to support answers the students believe to be reasonable when in reality deviated from the correct answer. An extensive study was developed to assess several distinctions between student intuition and use of cognition in problem solving, as related to a generalized student population. The study was comprised of a survey and interview. The survey utilized two instruments ...


Nano-Enhanced Biolubricant In Sustainable Manufacturing: From Processability To Mechanisms, Yanbin Zhang, Hao Nan Li, Changhe Li, Chuanzhen Huang, Hafiz Muhammad Ali, Xuefeng Xu, Cong Mao, Wenfeng Ding, Xin Cui, Min Yang, Tianbiao Yu, Muhammad Jamil, Munish Kumar Gupta, Dongzhou Jia, Zafar Said Jun 2022

Nano-Enhanced Biolubricant In Sustainable Manufacturing: From Processability To Mechanisms, Yanbin Zhang, Hao Nan Li, Changhe Li, Chuanzhen Huang, Hafiz Muhammad Ali, Xuefeng Xu, Cong Mao, Wenfeng Ding, Xin Cui, Min Yang, Tianbiao Yu, Muhammad Jamil, Munish Kumar Gupta, Dongzhou Jia, Zafar Said

Friction

To eliminate the negative effect of traditional metal-working fluids and achieve sustainable manufacturing, the usage of nano-enhanced biolubricant (NEBL) is widely researched in minimum quantify lubrication (MQL) machining. It’s improved tool wear and surface integrity have been preliminarily verified by experimental studies. The previous review papers also concluded the major influencing factors of processability including nano-enhancer and lubricant types, NEBL concentration, micro droplet size, and so on. Nevertheless, the complex action of NEBL, from preparation, atomization, infiltration to heat transfer and anti-friction, is indistinct which limits preparation of process specifications and popularity in factories. Especially in the complex machining ...


Tribological Behavior Of Co-Textured Cylinder Liner-Piston Ring During Running-In, Chenwei Miao, Zhiwei Guo, Chengqing Yuan Jun 2022

Tribological Behavior Of Co-Textured Cylinder Liner-Piston Ring During Running-In, Chenwei Miao, Zhiwei Guo, Chengqing Yuan

Friction

The running-in of cylinder liner-piston rings (CLPRs) is the most important process that must be performed before a marine diesel engine can be operated. The quality of running-in directly affects the reliability of a CLPR. The surface texture of a CLPR has been proven to significantly affect its lubrication performance. In this study, the tribological behavior of a CLPR during running-in is investigated. Three types of surface textures are generated on the CLPR via laser processing: dimple texture on piston rings, groove texture on cylinder liners, and co-texture on both sides. Subsequently, a series of tests are performed on a ...


Investigation Into Gas Lubrication Performance Of Porous Gas Bearing Considering Velocity Slip Boundary Condition, Xiangbo Zhang, Shuiting Ding, Farong Du, Fenzhu Ji, Zheng Xu, Jiang Liu, Qi Zhang, Yu Zhou Jun 2022

Investigation Into Gas Lubrication Performance Of Porous Gas Bearing Considering Velocity Slip Boundary Condition, Xiangbo Zhang, Shuiting Ding, Farong Du, Fenzhu Ji, Zheng Xu, Jiang Liu, Qi Zhang, Yu Zhou

Friction

Porous gas bearings (PGBs) have a proactive application in aerospace and turbomachinery. This study investigates the gas lubrication performance of a PGB with the condition of velocity slip boundary (VSB) owing to the high Knudsen number in the gas film. The Darcy-Forchheimer laws and modified Navier-Stokes equations were adopted to describe the gas flow in the porous layer and gas film region, respectively. An improved bearing experimental platform was established to verify the accuracy of the derived theory and the reliability of the numerical analysis. The effects of various parameters on the pressure distribution, flow cycle, load capacity, mass flow ...


Effect Of Wear Debris On Fretting Fatigue Crack Initiation, Shengjie Wang, Tongyan Yue, Dagang Wang, Magd Abdel Wahab Jun 2022

Effect Of Wear Debris On Fretting Fatigue Crack Initiation, Shengjie Wang, Tongyan Yue, Dagang Wang, Magd Abdel Wahab

Friction

Both wear and fatigue occur in fretting condition, and they interact with one another during the whole process. Fretting fatigue is commonly analysed without considering the effect of wear in partial slip regime, although wear affects the lifetime of crack initiation. This paper investigates, for the first time, the effect of wear debris on fretting fatigue crack initiation. To investigate the effect of debris, first fretting wear characteristics in partial slip regime are analysed for loading conditions. Then, the effect of wear on fretting fatigue crack initiation is investigated using Ruiz parameters and critical plane methods without considering the debris ...


Incipient Sliding Of Adhesive Contacts, Francesc Pérez-Ràfols, Lucia Nicola Jun 2022

Incipient Sliding Of Adhesive Contacts, Francesc Pérez-Ràfols, Lucia Nicola

Friction

A model is proposed herein to investigate the incipient sliding of contacts in the presence of both friction and adhesion, where the interfacial response is modeled based on traction-separation laws. A Maugis-like parameter is defined to characterize the response in the tangential direction. Subsequently, the model is used to investigate the contact between a smooth cylinder and a flat body, where adhesion-friction interactions are strong. A range of behaviors are observed when a tangential displacement is imposed: When the parameter is low, the contact pressure exhibits a relatively constant profile; when it is high, a pressure spike is observed at ...


Water-Based Lubrication Of Niobium Nitride, Kaifei Miao, Jia Wang, Qiang Zhao, Kaiwen Wang, Mao Wen, Kan Zhang Jun 2022

Water-Based Lubrication Of Niobium Nitride, Kaifei Miao, Jia Wang, Qiang Zhao, Kaiwen Wang, Mao Wen, Kan Zhang

Friction

Water-based lubrication has attracted wide attention as an oil-free lubrication method owing to its greener and cleaner lubrication means. However, due to operating in the water environment, most moving parts would inevitably suffer from abrasion, rusting, and aging problems. Developing a novel solid-water composite system with ultra-low friction and wear will open new possibilities for innovative lubrication material research and development. Here, we first revealed the water-based lubrication behavior of a high-hardness niobium nitride coating (NbN). In a three-phase contact environment (water, air, and NbN), oxidation and hydrolytic reactions of NbN result in the formation of "colloidal solutions", containing Nb ...


Enhanced Tribological Properties Of Aligned Graphene-Epoxy Composites, Yuefeng Du, Zhenyu Zhang, Dong Wang, Lezhen Zhang, Junfeng Cui, Yapeng Chen, Mingliang Wu, Ruiyang Kang, Yunxiang Lu, Jinhong Yu, Nan Jiang Jun 2022

Enhanced Tribological Properties Of Aligned Graphene-Epoxy Composites, Yuefeng Du, Zhenyu Zhang, Dong Wang, Lezhen Zhang, Junfeng Cui, Yapeng Chen, Mingliang Wu, Ruiyang Kang, Yunxiang Lu, Jinhong Yu, Nan Jiang

Friction

The random distribution of graphene in epoxy matrix hinders the further applications of graphene-epoxy composites in the field of tribology. Hence, in order to fully utilize the anisotropic properties of graphene, highly aligned graphene-epoxy composites (AGEC) with horizontally oriented structure have been fabricated via an improved vacuum filtration freeze-drying method. The frictional tests results indicated that the wear rate of AGEC slowly increased from 5.19×10-6 mm3/(N·m) to 2.87×10-5 mm3/(N·m) with the increasing of the normal load from 2 to 10 N, whereas the friction coefficient (COF) remained a ...


Optimizing The Tribological Performance Of Dlc-Coated Nbr Rubber: The Role Of Hydrogen In Films, Changning Bai, Li Qiang, Bin Zhang, Kaixiong Gao, Junyan Zhang Jun 2022

Optimizing The Tribological Performance Of Dlc-Coated Nbr Rubber: The Role Of Hydrogen In Films, Changning Bai, Li Qiang, Bin Zhang, Kaixiong Gao, Junyan Zhang

Friction

Diamond-like carbon (DLC) films directly deposited on rubber substrate is undoubtedly one optimal option to improve the tribological properties due to its ultralow friction, high-hardness as well as good chemical compatibility with rubber. Investigating the relationship between film structure and tribological performance is vital for protecting rubber. In this study it was demonstrated that the etching effect induced by hydrogen incorporation played positive roles in reducing surface roughness of DLC films. In addition, the water contact angle (CA) of DLC-coated nitrile butadiene rubber (NBR) was sensitive to the surface energy and sp2 carbon clustering of DLC films. Most importantly ...


Experimental And Modelling Studies Of The Transient Tribological Behaviour Of A Two-Phase Lubricant Under Complex Loading Conditions, Xiao Yang, Lemeng Zhang, Denis J. Politis, Jie Zhang, Mohammad M. Gharbi, David Leyvraz, Liliang Wang Jun 2022

Experimental And Modelling Studies Of The Transient Tribological Behaviour Of A Two-Phase Lubricant Under Complex Loading Conditions, Xiao Yang, Lemeng Zhang, Denis J. Politis, Jie Zhang, Mohammad M. Gharbi, David Leyvraz, Liliang Wang

Friction

The transient tribological phenomenon and premature lubricant breakdown have been widely observed in metal forming, leading to excessive friction at the contact interfaces. In this research, the transient tribological behaviour of a two-phase lubricant were studied under complex loading conditions, featuring abrupt interfacial temperature, contact load, and sliding speed changes, thus representing the severe interfacial conditions observed in warm/hot metal forming applications. The strong experimental evidence indicates that the evolution of friction was attributed to the physical diminution and chemical decomposition effects. As such, a visco-mechanochemical interactive friction model was developed to accurately predict the transient tribological behaviour of ...


A Finite-Element-Aided Ultrasonic Method For Measuring Central Oil-Film Thickness In A Roller-Raceway Tribo-Pair, Pan Dou, Tonghai Wu, Zhaopeng Luo, Peiping Yang, Zhongxiao Peng, Min Yu, Tom Reddyhoff Jun 2022

A Finite-Element-Aided Ultrasonic Method For Measuring Central Oil-Film Thickness In A Roller-Raceway Tribo-Pair, Pan Dou, Tonghai Wu, Zhaopeng Luo, Peiping Yang, Zhongxiao Peng, Min Yu, Tom Reddyhoff

Friction

Roller bearings support heavy loads by riding on an ultra-thin oil film (between the roller and raceway), the thickness of which is critical as it reflects the lubrication performance. Ultrasonic interfacial reflection, which facilitates the non-destructive measurement of oil-film thickness, has been widely studied. However, insufficient spatial resolution around the rolling line contact zone remains a barrier despite the use of miniature piezoelectric transducers. In this study, a finite-element-aided method is utilized to simulate wave propagation through a three-layered structure of roller-oil-raceway under elastohydrodynamic lubrication (EHL) with nonlinear characteristics of the i) deformed curvature of the cylindrical roller and ii ...


Utilization Of Steel Slag In Development Of Sustainable And Durable Concrete., Karthik Prabhu T Dr, Gowri Shankar M Mr., Jagadesh P Dr., Nagarajan V Dr. May 2022

Utilization Of Steel Slag In Development Of Sustainable And Durable Concrete., Karthik Prabhu T Dr, Gowri Shankar M Mr., Jagadesh P Dr., Nagarajan V Dr.

International Journal of Advanced Technology in Civil Engineering

This paper reflects the results of an experimental investigation of the strength, permeability, abrasion, carbonation, and shrinkage characteristics of concrete containing various percentages of steel slag as partial replacement of natural fine aggregates. M 30 Grade concrete was designed as per specific national specifications. Steel slag was used to replace natural sand in the range of 0– 50%. It was observed that the steel slag blended concrete with up to 50% substitution exhibited a comparable compressive and flexural strength when compared to the control specimens. From the Dorry’s abrasion test, it was noted that the specimens could be implemented ...


Methodology To Aircraft Design – Market Study & Design Optimization, Shreyash Attarkar, Dhananjay Ahire, Tanishq Pawar, Suresh Kumar M Prof. May 2022

Methodology To Aircraft Design – Market Study & Design Optimization, Shreyash Attarkar, Dhananjay Ahire, Tanishq Pawar, Suresh Kumar M Prof.

Graduate Research in Engineering and Technology (GRET)

In the last few years Aircraft have grown to be large-scale products with an increasing number of complicated systems, components, parts, and capabilities. Every single one of them. Various fields and technologies are included. Multiple sets of tools, procedures and methods are also included, as a result, to fully define, design, and develop an aircraft A comprehensive and methodic approach is required. Aircraft design that serves as a pillar in the evolution of the life cycle A balanced system solution that satisfies the needs of the customer. To accompany these characteristics. system engineering provides an interdisciplinary organization but is still ...


Impact Of The Ban On Illegal Mining Activities On Raw Water Quality: A Case-Study Of Konongo Water Treatment Plant, Ashanti Region Of Ghana, Sadique Anyame Bawa, Prince Antwi-Agyei, Martin Kyereh Domfeh May 2022

Impact Of The Ban On Illegal Mining Activities On Raw Water Quality: A Case-Study Of Konongo Water Treatment Plant, Ashanti Region Of Ghana, Sadique Anyame Bawa, Prince Antwi-Agyei, Martin Kyereh Domfeh

Journal of Sustainable Mining

The Government of Ghana prohibited Artisanal and Small-Scale Mining (ASM) operations from 2017 to 2018 as part of its strategy to address the socio-environmental issues caused by illegal mining activities, also referred to as “galamsey” operations. This study assessed the trend in the water quality of raw water abstracted at the Konongo Water Treatment Plant (WTP) for treatment before and after implementing the ban on “galamsey” operations. The main source of raw water for the Konongo WTP is the Anuru River. Secondary data on physicochemical water quality from 2006 to 2019 was sourced from the Konongo WTP and the Ashanti ...


Improved Methodology For Monitoring The Impact Of Mining Activities On Socio-Economic Conditions Of Local Communities, Binay Prakash Pandey, Devi Prasad Mishra May 2022

Improved Methodology For Monitoring The Impact Of Mining Activities On Socio-Economic Conditions Of Local Communities, Binay Prakash Pandey, Devi Prasad Mishra

Journal of Sustainable Mining

Mining activities can cause tangible socio-economic improvements in the surrounding regions. Such potential has not been fully realized, owing to the fact that the socio-economic impact assessment processes exercised in India merely predict the footprint of industrial activity on the surrounding population. Consequently, project proponents are mandated to implement a management plan in cases of foreseeable negative consequences. However, both, the assessment study, as well as the process of implementation of a management plan, are riddled with significant gaps and limitations. Primary data collected for this research makes it apparent that, in comparison to the revenue generated from the mining ...


Classification Of Internet Advertisement, Biswajit Biswal, Banasmita Subhadarshini, Sasmita Jena, Binita Kumari May 2022

Classification Of Internet Advertisement, Biswajit Biswal, Banasmita Subhadarshini, Sasmita Jena, Binita Kumari

Graduate Research in Engineering and Technology (GRET)

The investigation of web ad is vital now daily in human existence. Commercial and their connected regions are economy concern business has become an outstanding field in the wide spread region. Publicizing area are producing part of data and information which help to comprehend and should be examination, propositions information are should change over into significant information. To utilize these clients' data, settle on future choice and accomplish powerful choices, these choices help to comprehend client's need and utilization of the labour and products. Utilize client's information and carry out information mining strategies to get familiar with clients ...


Speech Emotion Recognition System Using Librosa For Better Customer Experience, Subhadarshini Mohanty, Subasish Mohapatra, Amlan Sahoo May 2022

Speech Emotion Recognition System Using Librosa For Better Customer Experience, Subhadarshini Mohanty, Subasish Mohapatra, Amlan Sahoo

Graduate Research in Engineering and Technology (GRET)

Call center employees usually depend on instinct to judge a potential customer and how to pitch to them. In this paper, we pitch a more effective way for call center employees to generate more leads and engagement to generate higher revenue by analyzing the speech of the target customer by using machine learning practices and depending on data to make data-driven decisions rather than intuition. Speech Emotion Recognition otherwise known as SER is the demonstration of aspiring to perceive human inclination along with the behavior. Normally voice reflects basic feeling through tone and pitch. According to human behavior, many creatures ...


Forecasting The Time Delay In Delivery Of Pharmaceutical Products, Subhalaxmi Hotta, Sonali Sahoo, Tripti Swarnkar May 2022

Forecasting The Time Delay In Delivery Of Pharmaceutical Products, Subhalaxmi Hotta, Sonali Sahoo, Tripti Swarnkar

Graduate Research in Engineering and Technology (GRET)

Supply chain management system is a centralized system which controls and plans the activities involved from production to delivery of a product. Disruption in treatment and loss of life occurs due to delay in delivery of pharmaceutical products. The objective is to do a model using Machine learning algorithms to determine: Classification to predict which product will be delayed and Regression shows how much time it will be delayed exactly. This study will use publicly available supply chain data which helps to identify primary aspect of predicting whether HIV drugs are delivered in time or not. It will then use ...


Fortune Of Smart-Phones By A Model Recommendation, Sonali Sahoo, Subhalaxmi Hotta, Tripti Swarnkar May 2022

Fortune Of Smart-Phones By A Model Recommendation, Sonali Sahoo, Subhalaxmi Hotta, Tripti Swarnkar

Graduate Research in Engineering and Technology (GRET)

In recent market, there are several cell phones available, Smart phones differ based on their Operating system. Here we are going to do a comparison between two Operating systems i.e., “IOS and ANDROID”. The comparison starts including the basic features of smart phones. The features are varying from each other. Some of them are categorical and some are numerical. According to these data, classify the smart phones using machine learning classification model. After the classification we are going to analyse which operating system-based Smartphone will be taken for further classification. A “Recommendation system”, will be designed which recommend a ...


Iot In Healthcare Domain, Manisha Banka, Ankita Mishra, Sushreeta Tripathy May 2022

Iot In Healthcare Domain, Manisha Banka, Ankita Mishra, Sushreeta Tripathy

Graduate Research in Engineering and Technology (GRET)

In the current scenario, the Internet of Things (IoT) is an emerging technology. IoT is a new pattern that has changed the long-established way of living into a modernistic life style. IoT is the network of physical objects, which enables to collect data and exchange it without human intervention. In general, IoT has been established to interlink the latest healthcare resources and to provide smart and efficient healthcare facilities to the people. IoT allows objects to be sensed and controlled remotely across existing network infrastructure. Health maintenance has become a considerable socio-economic concern when it comes to health expenses, need ...


Application Of Text Mining In Social Media, Gopal Krushna Padhi, Sushreeta Tripathy May 2022

Application Of Text Mining In Social Media, Gopal Krushna Padhi, Sushreeta Tripathy

Graduate Research in Engineering and Technology (GRET)

Text mining or information discovery is that sub manner of information mining that is extensively being used to find out hidden styles and huge records from the massive amount of unstructured written fabric. Text mining allows accelerate know-how discovery by way of notably growing the amount records that can be analyzed. Rapid development in digital facts acquisition strategies have caused huge extent of facts. More than 80 percentages of these day’s statistics is composed of unstructured or semi-based information. This sort of data cannot be used until or unless particular records or pattern is determined. The discovery of appropriate ...


A Machine Learning Based Drug Recommendation System For Health Care, Mahima Mohapatra, Mamata Nayak, Saswati Mahapatra May 2022

A Machine Learning Based Drug Recommendation System For Health Care, Mahima Mohapatra, Mamata Nayak, Saswati Mahapatra

Graduate Research in Engineering and Technology (GRET)

In today’s digital era healthcare is one among the major core areas of the medical domain. People trying to find suitable health-related information that they are concerned with. The Internet could be a great resource for this kind of data, however you need to take care to avoid getting harmful information. Nowadays, a colossal quantity of clinical information dispersed totally across different websites on the Internet prevents users from finding useful information for their well-being improvement. Errors in medication are one of the foremost severe medical faults that would be a threat to patients’ lives. These problems increases the ...


Benford’S Law For Data Cleaning In Big Data, Prachurya Ray May 2022

Benford’S Law For Data Cleaning In Big Data, Prachurya Ray

Graduate Research in Engineering and Technology (GRET)

With the exponential increase in data, the need to authenticate the integrity accuracy of the data also increases. Regarded as a mysterious law, Benford's Law has seen many use cases over the centuries ranging from detecting fraud in accounting to checking for GAN generated images. This First digit law has helped finding anomalies in various data across many domains. This paper summarizes what this mysterious law is and implements the same to asteroid data to check for the pattern. This law has the potential to handle the growing need for authenticity for the big data revolution. Further research on ...


A Proper Borehole Pattern Design For Coal Seam Methane Drainage In Tabas Coal Mine Using Comsol Multiphysics, Ali Bagherzadeh, Mehdi Najafi, Mohammad Fatehi Marji, Mehdi Noroozi May 2022

A Proper Borehole Pattern Design For Coal Seam Methane Drainage In Tabas Coal Mine Using Comsol Multiphysics, Ali Bagherzadeh, Mehdi Najafi, Mohammad Fatehi Marji, Mehdi Noroozi

Journal of Sustainable Mining

Optimizing the operational parameters of the borehole pattern in the coal seam includes the maximum amount of gas to be drained with the least amount of drilling, investment, and drainage time. The main purpose of this research is to properly design the drainage borehole pattern in the C1 coal seam of the Tabas coal mine. In this research, the Comsol Multiphysics software was used for numerical modeling of the boreholes. According to the method of diffusion of methane gas in a coal seam, the reduction of methane gas concentration and the amount of gas released from the coal blocks were ...


In Situ Observations Of Fish Attraction To Light-Emitting Diodes On An Undersea Observation Deck, Makoto Tomiyasu, Yoko Tanouchi, Yasuzumi Fujimori, Minato Kaji, Takuma Hayashi, Naoto Matsubara, Hiroki Yasuma, Susumu Shimizu, Seiji Katakura May 2022

In Situ Observations Of Fish Attraction To Light-Emitting Diodes On An Undersea Observation Deck, Makoto Tomiyasu, Yoko Tanouchi, Yasuzumi Fujimori, Minato Kaji, Takuma Hayashi, Naoto Matsubara, Hiroki Yasuma, Susumu Shimizu, Seiji Katakura

Journal of Marine Science and Technology

Many fisheries employ fishing lights to manipulate the behaviors of target fish and to attract them toward the light; however, relatively few long-time observations of fish attraction have been performed in the field. Here, an underwater observation deck was used to examine the differences in the fish-attracting effect of light-emitting diode (LED) lights on the number of attracted fish and on their behavior in the field, using white-edged rockfish as the target species. A total of 604 ± 324, 307 ± 203 and 171 ± 106 white-edged rockfish individuals were attracted to the observation window when it was illuminated with blue, green, and ...


Inter-Annual Variability In Growth And Maturation Of The Swordtip Squid Uroteuthis Edulis In Yilan Bay Off Northeastern Taiwan, Jing-Yu Chen, Tzu-Yun Ching, Chih-Shin Chen May 2022

Inter-Annual Variability In Growth And Maturation Of The Swordtip Squid Uroteuthis Edulis In Yilan Bay Off Northeastern Taiwan, Jing-Yu Chen, Tzu-Yun Ching, Chih-Shin Chen

Journal of Marine Science and Technology

The swordtip squid Uroteuthis edulis, distributed in the temperate and tropical neritic waters in the Indo-Pacific region, is a crucial component of marine ecosystems and is a target species of fisheries in the Northwest Pacific. Although studies have elucidated the growth and maturation of the squid in the southern East China Sea (ECS) shelf, few have assessed the population biology of the squid in waters in the vicinity of the southern ECS. We collected samples of swordtip squid from a trawler in Yilan Bay (YLB) between January 2011 and December 2012 to examine the growth and maturation of the squid ...


Study On The Improved Radiation Boundary Conditions Based On The Quadratic B-Spline Rankine Panel Method, Ming-Chung Fang, Chun-Hsien Wu May 2022

Study On The Improved Radiation Boundary Conditions Based On The Quadratic B-Spline Rankine Panel Method, Ming-Chung Fang, Chun-Hsien Wu

Journal of Marine Science and Technology

This study presents a higher-order Rankine source method that is based on a biquadratic B-spline scheme with an improved radiation boundary condition. This method solves flow problems under all conditions, where , including the undercritical condition ( < 0.25); this condition is present when a ship undergoes slow translational motion. The proposed method is thus more flexible than the many Rankine-source models in the literature that are applicable only to the overcritical condition ( > 0.25). Specifically, the improved radiation boundary condition is derived from upstream Seto radiation boundary conditions and by incorporating the Rayleigh damping distribution over a free surface; the improved condition is explicit and efficient for solving flow problems. In evaluations, the proposed method yields accurate solutions for unsteady flows, which are produced by an oscillating, translationally moving submerged singularity. The method is also compared against ...


Sensitive Analysis Of The Static Response Of Compliant Vertical Access Risers, Fuheng Li, Haiyan Guo, Xiaomin Li, Honglu Gu May 2022

Sensitive Analysis Of The Static Response Of Compliant Vertical Access Risers, Fuheng Li, Haiyan Guo, Xiaomin Li, Honglu Gu

Journal of Marine Science and Technology

Compliant vertical access risers (CVARs) are considered as efficient and robust alternative options to achieve cost efficiency and safety. Design uncertainties emerge owing to the limited understanding of the effects of various parameters related to the structural properties and marine loads. In this paper, a reasonable three-dimensional (3D) numerical model of CVAR with internal flow is presented based on the slender rod theory. Accordingly, the finite element method combined with a Newton-Raphson scheme is employed to discretize and solve the equations. A sensitivity analysis is performed to investigate the influence of the structural and external load parameters on the static ...


Influence Of Boundary Conditions And Internal Fluid Types On Dynamic Characteristics Of A Deepwater Riser, Lei Guo, Zong-Ming Zhu, Zhong-Jian Pan, Zhi-Ming Guo May 2022

Influence Of Boundary Conditions And Internal Fluid Types On Dynamic Characteristics Of A Deepwater Riser, Lei Guo, Zong-Ming Zhu, Zhong-Jian Pan, Zhi-Ming Guo

Journal of Marine Science and Technology

Deepwater Steel Catenary Riser (DSCR) is the key structure of oil and gas production system in the ocean. To design an optimized DSCR system, the dynamic characteristics of the DSCR are analyzed by setting some different boundary condi-tions and internal fluid types. The main vibration mode of the DSCR is found orthogonal to both mass and stiffness according to the normalization condition of the main mode, and then the regular mode function and the jth order principal stiffness Kpj are obtained. Under different initial conditions, the transverse responses of DSCR represented by regular coordinates under arbitrary excitation are obtained. Then ...


Variance Of Td-Mosaic Dual-Vortex Interactions Between In-Fa And Cempaka (2021) In The North Pacific, Tsorng-Lin Chia, Guang-Yang Pan, Ji-Chyun Liu May 2022

Variance Of Td-Mosaic Dual-Vortex Interactions Between In-Fa And Cempaka (2021) In The North Pacific, Tsorng-Lin Chia, Guang-Yang Pan, Ji-Chyun Liu

Journal of Marine Science and Technology

A study of the different types of dual-vortex interactions or “Fujiwara effects” between two storms is crucial for considerably improving weather forecasts. This study combined remote sensing images, empirical formulas based on the possibility of storm interaction (Liou–Liu formula), and vector addition techniques to accurately analyze In-Fa and Cempaka typhoons and the surrounding weather patterns during the 2021 typhoon season in the North Pacific. Although the distance separating the typhoons In-Fa and Cempaka was 1,800–2,040 km, the influence of middle air flow and a tropical depression (TD) caused a "vector superposition TD-mosaic double-vortex" interaction between the ...