Journal of Marine Science and Engineering

12 pages, 4178 KiB

Open AccessArticle

Effective Mistuning Identification Method of Integrated Bladed Discs of Marine Engine Turbochargers

by Václav Píštěk, Pavel Kučera, Oleksij Fomin and Alyona Lovska

J. Mar. Sci. Eng. 2020, 8(5), 379; https://doi.org/10.3390/jmse8050379 - 25 May 2020

Cited by 34 | Viewed by 2728

Radial turbine and compressor wheels form essential cornerstones of modern internal combustion engines in terms of economy, efficiency and, in particular, environmental compatibility. As a result of the introduction of exhaust gas turbochargers in the extremely important global market for diesel engines, higher [...] Read more.

Radial turbine and compressor wheels form essential cornerstones of modern internal combustion engines in terms of economy, efficiency and, in particular, environmental compatibility. As a result of the introduction of exhaust gas turbochargers in the extremely important global market for diesel engines, higher engine efficiencies are possible, which in turn reduce fuel consumption. The associated reduced exhaust emissions can answer questions that results from environmentally relevant aspects of the engine development. In shipping, the international Maritime Organisation (IMO) prescribes the step-by-step reduction of nitrogen oxide and other types of emissions. To reduce these emissions, various systems are being developed, in which turbochargers are an important part. The requirements for the reliability and service life of turbochargers are constantly increasing. Turbocharger blade vibration is one of the most important problems to be solved when designing the rotors. In the case of real rotors, so-called mistuning arises, which is a slight deviation of the properties of the individual blades from the design parameters. The article deals with an effective method of mistuning identification for cases of integrated bladed discs of marine engine turbochargers. Unlike approaches that use costly scanning laser Doppler vibrometers, this method is based on using only a simple laser vibrometer in combination with a computational model of the integrated bladed disc. The added value of this method is, in particular, a significant reduction in the cost of laboratory equipment and a reduction in the time required to obtain the results. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

► Show Figures

Figure 1

21 pages, 9156 KiB

Open AccessArticle

Manoeuvrability of a Large Cruise Ship after Damage for Safe Return to Port

by Tetsuhiro Yuura, Hirotada Hashimoto and Akihiko Matsuda

J. Mar. Sci. Eng. 2020, 8(5), 378; https://doi.org/10.3390/jmse8050378 - 25 May 2020

Cited by 1 | Viewed by 2678

Abstract

Free-running model tests were conducted using a scaled model of a large cruise ship with a damaged compartment, to investigate the effects of damage opening and floodwater on the manoeuvring performance in calm water and regular and irregular head waves. Drifting tests in [...] Read more.

Free-running model tests were conducted using a scaled model of a large cruise ship with a damaged compartment, to investigate the effects of damage opening and floodwater on the manoeuvring performance in calm water and regular and irregular head waves. Drifting tests in regular beam waves were also performed. The experimental results indicated that the course-keeping ability in waves and turning ability became worse in the damaged condition. However, the target ship retained its manoeuvrability for safe return to the port, on its own, even in a damaged state. As it is time- and cost-consuming to conduct a free-running model experiment, a captive model test was also carried out to develop a system-based simulation model for evaluating the manoeuvrability of large cruise ships after damage. Full article

(This article belongs to the Special Issue Safety Assessment of Ships and Offshore Structures under Severe Condition)

► Show Figures

Figure 1

15 pages, 7544 KiB

Open AccessFeature PaperArticle

Prediction of the Side Drift Force of Full Ships Advancing in Waves at Low Speeds

by Shukui Liu and Apostolos Papanikolaou

J. Mar. Sci. Eng. 2020, 8(5), 377; https://doi.org/10.3390/jmse8050377 - 25 May 2020

Cited by 8 | Viewed by 3127

Abstract

In this study, we analyze the experimental results of the mean sway (side drift) forces of six full type ships at low speeds in regular waves of various directions and compare them with numerical results of the in-house 3D panel code NEWDRIFT. It [...] Read more.

In this study, we analyze the experimental results of the mean sway (side drift) forces of six full type ships at low speeds in regular waves of various directions and compare them with numerical results of the in-house 3D panel code NEWDRIFT. It is noted that the mean sway force is most significant in relatively short waves, with the peak being observed at λ/L_PP ≈ 0.5–0.6. For λ/L_PP > 1.0, the corresponding value is rather small. We also observe a solid recurring pattern of the mean sway force acting on the analyzed full type ships. On this basis, we proceed to approximate the mean sway force with an empirical formula, in which only the main ship particulars and wave parameters are used. Preliminary validation results show that the developed empirical formula, which is readily applicable in practice, can accurately predict the mean sway force acting on a full ship, at both zero and non-zero speeds. Full article

(This article belongs to the Special Issue Ship Dynamics for Performance Based Design and Risk Averse Operations)

► Show Figures

Figure 1

19 pages, 4277 KiB

Open AccessArticle

Development of Machine Learning Strategy for Predicting the Risk Range of Ship’s Berthing Velocity

by Hyeong-Tak Lee, Jeong-Seok Lee, Woo-Ju Son and Ik-Soon Cho

J. Mar. Sci. Eng. 2020, 8(5), 376; https://doi.org/10.3390/jmse8050376 - 24 May 2020

Cited by 20 | Viewed by 3429

Abstract

Ships are prone to accidents when approaching in a berthing velocity greater than that allowed when determining the risk range corresponding to a port. Therefore, this study develops a machine learning strategy to predict the risk range of an unsafe berthing velocity when [...] Read more.

Ships are prone to accidents when approaching in a berthing velocity greater than that allowed when determining the risk range corresponding to a port. Therefore, this study develops a machine learning strategy to predict the risk range of an unsafe berthing velocity when the ship approaches in port. To perform analysis, the input parameters were based on the factors affecting the berthing velocity, and the output parameter, i.e., the berthing velocity, was measured at a tanker terminal in the Republic of Korea. Nine machine learning classification algorithms were used to analyze each model, and the top four optimal models were selected through evaluation methods based on the confusion matrix. As a result of the analysis, extra trees, random forest, bagging, and gradient boosting classifiers were identified as good models. As a result of testing using the receiving operator characteristic curve, it was confirmed that the area under the curve of the most dangerous range of berthing velocity was the highest, thus, the risk range was appropriately classified. As such, the derived models can classify and predict the risk range of unsafe berthing velocity before approaching a port; therefore, it is possible to safely berth a ship. Full article

(This article belongs to the Special Issue Maritime Safety)

► Show Figures

Figure 1

20 pages, 8882 KiB

Open AccessArticle

Verification of Novel Maritime Route Extraction Using Kernel Density Estimation Analysis with Automatic Identification System Data

by Jeong-Seok Lee, Woo-Ju Son, Hyeong-Tak Lee and Ik-Soon Cho

J. Mar. Sci. Eng. 2020, 8(5), 375; https://doi.org/10.3390/jmse8050375 - 24 May 2020

Cited by 19 | Viewed by 3270

Abstract

A maritime route is used by sea transportation vessels to access the trading ports, and route design standards for the safety of maritime traffic have been established in various countries and organizations. However, no quantitative safety verification method related to route design currently [...] Read more.

A maritime route is used by sea transportation vessels to access the trading ports, and route design standards for the safety of maritime traffic have been established in various countries and organizations. However, no quantitative safety verification method related to route design currently exists. In this study, a novel maritime route was created and compared with the original route in Incheon, the Republic of Korea, based on the relevant automatic identification system (AIS) data. The attendant traffic density was revealed via kernel density estimation analysis of the AIS data, with the results used to create the boundary of the novel route through an image processing technique. The boundary and the centerline of the maritime route were determined using a line smoothing technique. For safety verification, the centerline of the original route and that of the novel maritime route were compared in terms of sinuosity, intersection angle, and route change envelope (RCE). The sinuosity analysis demonstrated that the route was stable in terms of the outer harbor limit, while the intersection angle analysis demonstrated that the novel maritime route intersection angle was stable. The RCE was used to objectively compare the absolute values of the distance change in the centerline. Full article

(This article belongs to the Special Issue Maritime Safety)

► Show Figures

Figure 1

22 pages, 3970 KiB

Open AccessArticle

Development of Competitive–Cooperative Relationships among Mediterranean Cruise Ports since 2000

by Vivien Lorenčič, Elen Twrdy and Milan Batista

J. Mar. Sci. Eng. 2020, 8(5), 374; https://doi.org/10.3390/jmse8050374 - 24 May 2020

Cited by 6 | Viewed by 2985

Abstract

Cruise shipping has been extremely popular in recent years, and one of the fastest-growing areas has been the Mediterranean. In the paper, we examine the evaluation of possible competitive–cooperative relationships among Mediterranean cruise ports for the period 2000–2017. To this end, we use [...] Read more.

Cruise shipping has been extremely popular in recent years, and one of the fastest-growing areas has been the Mediterranean. In the paper, we examine the evaluation of possible competitive–cooperative relationships among Mediterranean cruise ports for the period 2000–2017. To this end, we use three models: the dynamic shift-share model, the Lotka–Volterra model (LVM), and the logistic model (LM). The evaluation of basic market indices is included for completeness. The analysis shows that cruise traffic is in a saturation phase. The shift-share and LVM models reveal that interaction among ports is not significant for the large ports, but could be essential for the small ones. Full article

(This article belongs to the Section Coastal Engineering)

► Show Figures

Figure 1

30 pages, 19079 KiB

Open AccessFeature PaperArticle

Computational Modelling of the Impacts of Saltmarsh Management Interventions on Hydrodynamics of a Small Macro-Tidal Estuary

by William G. Bennett, Thomas J. van Veelen, Tom P. Fairchild, John N. Griffin and Harshinie Karunarathna

J. Mar. Sci. Eng. 2020, 8(5), 373; https://doi.org/10.3390/jmse8050373 - 23 May 2020

Cited by 12 | Viewed by 4006

Abstract

Saltmarshes are considered as natural coastal defences. However, owing to the large context dependency, there is much discussion over their effectiveness in providing coastal protection and the necessity of additional coastal defence interventions. The macro-tidal Taf Estuary in south-west Wales was chosen as [...] Read more.

Saltmarshes are considered as natural coastal defences. However, owing to the large context dependency, there is much discussion over their effectiveness in providing coastal protection and the necessity of additional coastal defence interventions. The macro-tidal Taf Estuary in south-west Wales was chosen as the case study in this paper to investigate the effects of anthropogenic coastal defence interventions such as construction of hard defences, managed realignment, and altering land use of the saltmarshes on the complex hydrodynamics of the estuary. A coupled flow–wave–vegetation model, developed using the Delft3D coastal modelling software, was used. The wave and current attenuation role of saltmarshes during two contrasting storm conditions was modelled, with and without saltmarsh management interventions. The study reveals that certain saltmarsh management interventions can have widespread impacts on the hydrodynamics of the estuary. Altering the land use by allowing extensive grazing of saltmarsh by livestock was found to have the largest impact on wave attenuation, where wave heights on the marsh almost doubled when compared with the no-intervention scenario. On the other hand, managed realignment has a significant impact on tidal currents, where tidal currents reached 0.5 m/s at certain locations. Changes in estuarine hydrodynamics can lead to undesired impacts on flooding and erosion, which stresses the importance of understanding the effects of localized anthropogenic coastal management interventions on the entire estuarine system. Full article

(This article belongs to the Special Issue Resilient Flood Defences)

► Show Figures

Figure 1

19 pages, 2752 KiB

Open AccessFeature PaperArticle

An Integrated Reconstruction of the Multiannual Wave Pattern in the Gulf of Naples (South-Eastern Tyrrhenian Sea, Western Mediterranean Sea)

by Simona Saviano, Daniela Cianelli, Enrico Zambianchi, Fabio Conversano and Marco Uttieri

J. Mar. Sci. Eng. 2020, 8(5), 372; https://doi.org/10.3390/jmse8050372 - 23 May 2020

Cited by 13 | Viewed by 2819

Abstract

Surface gravity waves retrieved by a network of HF (High Frequency) radars and measured in situ by an ADCP (Acoustic Doppler Current Profiler) current meter connected to an elastic beacon were used to carry out a multiple-year characterization of the wave field of [...] Read more.

Surface gravity waves retrieved by a network of HF (High Frequency) radars and measured in situ by an ADCP (Acoustic Doppler Current Profiler) current meter connected to an elastic beacon were used to carry out a multiple-year characterization of the wave field of the Gulf of Naples (south-eastern Tyrrhenian Sea, western Mediterranean). The aim of the work was to create a climatology of the study area and to demonstrate the potential of an integrated platform for coastal studies. The patterns recorded by the different instruments were in agreement with the wave climatology of the southern Tyrrhenian Sea as well as with previous scores for the same area. The results presented in this work also highlight seasonal and interannual consistency in the wave patterns for each site. In a wider context, this study demonstrates the potential of HF radars as long-term monitoring tools of the wave field in coastal basins, and supports the development of integrated observatories to address large-scale scientific challenges such as coastal ocean dynamics and the impact of global change on the local dynamics. Full article

(This article belongs to the Special Issue Radar Technology for Coastal Areas and Open Sea Monitoring)

► Show Figures

Figure 1

24 pages, 1080 KiB

Open AccessFeature PaperArticle

Propagation and Depolarization of a Short Pulse of Light in Sea Water

by Evgeniy E. Gorodnichev, Kirill A. Kondratiev, Alexandr I. Kuzovlev and Dmitrii B. Rogozkin

J. Mar. Sci. Eng. 2020, 8(5), 371; https://doi.org/10.3390/jmse8050371 - 23 May 2020

Cited by 3 | Viewed by 2483

Abstract

We present the results of a theoretical study of underwater pulse propagation. The vector radiative transfer equation (VRTE) underlies our calculations of the main characteristics of the scattered light field in the pulse. Under the assumption of highly forward scattering in seawater, three [...] Read more.

We present the results of a theoretical study of underwater pulse propagation. The vector radiative transfer equation (VRTE) underlies our calculations of the main characteristics of the scattered light field in the pulse. Under the assumption of highly forward scattering in seawater, three separate equations for the basic modes are derived from the exact VRTE. These three equations are further solved both within the small-angle approximation and numerically. The equation for the intensity is analyzed for a power-law parametrization of the wings of the sea water phase function. The distribution of early arrival photons in the pulse, including the peak intensity, is calculated. Simple relations are also presented for the variance of the angular distribution of radiation, the effective duration of the signal and other parameters of the pulse. For linearly and circularly polarized pulses, the temporal profile of the degree of polarization is calculated for actual data on the scattering matrix elements. The degree of polarization is shown to be described by the self-similar dependence on some combination of the transport scattering coefficient, the temporal delay and the source-receiver distance. Our results are in agreement with experimental and Monte-Carlo simulation data. The conclusions of the paper offer a theoretical groundwork for application to underwater imaging, communication and remote sensing. Full article

(This article belongs to the Special Issue Light Fields in the Ocean from Natural and Artificial Sources)

► Show Figures

Figure 1

10 pages, 7010 KiB

Open AccessArticle

Development of Broadband Underwater Radio Communication for Application in Unmanned Underwater Vehicles

by Igor Smolyaninov, Quirino Balzano and Dendy Young

J. Mar. Sci. Eng. 2020, 8(5), 370; https://doi.org/10.3390/jmse8050370 - 23 May 2020

Cited by 13 | Viewed by 3475

Abstract

This paper presents several novel designs of small form factor underwater radio antennas operating in the 2 MHz, 50 MHz and 2.4 GHz bands. These antennas efficiently excite surface electromagnetic waves (SEW) which propagate along the surface of seawater. The antenna operation is [...] Read more.

This paper presents several novel designs of small form factor underwater radio antennas operating in the 2 MHz, 50 MHz and 2.4 GHz bands. These antennas efficiently excite surface electromagnetic waves (SEW) which propagate along the surface of seawater. The antenna operation is made possible due to implementation of an impedance matching enclosure, which is filled with de-ionized water. Enhanced coupling to surface electromagnetic waves is enabled by the enhancement of the electromagnetic field at the antenna apex. These features allow us to make antenna dimensions considerably smaller compared to typical free space designs. They also considerably improve coupling of electromagnetic energy to the surrounding seawater. Since SEW propagation length is considerably larger than the skin depth in seawater, this technique is useful for underwater broadband wireless communication. We conclude that the developed broadband underwater radio communication technique will be useful in networking of unmanned underwater vehicles. Full article

(This article belongs to the Special Issue Unmanned Underwater Vehicles: Advances and Applications)

► Show Figures

Figure 1

21 pages, 4378 KiB

Open AccessArticle

A Fast Algorithm for Onboard Progressive Flooding Simulation

by Luca Braidotti and Francesco Mauro

J. Mar. Sci. Eng. 2020, 8(5), 369; https://doi.org/10.3390/jmse8050369 - 22 May 2020

Cited by 16 | Viewed by 1959

Abstract

The need for decision support after a flooding casualty requires the development of fast and accurate progressive flooding simulation procedures. Here, a new quasi-static technique is presented, proposing a differential algebraic formulation capable to consider independently the flooding process in the internal rooms. [...] Read more.

The need for decision support after a flooding casualty requires the development of fast and accurate progressive flooding simulation procedures. Here, a new quasi-static technique is presented, proposing a differential algebraic formulation capable to consider independently the flooding process in the internal rooms. The proposed method is efficient while simulating long flooding chains along rooms connected by similar size openings, a condition that likely occurs on large passenger ships. Moreover, the computational performances of the simulation procedure have been enhanced by adapting the time step to the progressive flooding pace. The adoption of an adaptive time step algorithm reduces significantly the calculation time. The novel procedure has been tested on the recommended benchmark cases for flooding simulations, highlighting the accuracy and flexibility of the proposed method. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

13 pages, 5949 KiB

Open AccessArticle

Model Tests on the Penetration Resistance of Bucket Foundations for Offshore Wind Turbines in Sand

by Hongyan Ding, Yanjian Peng, Puyang Zhang, Hanbo Zhai and Nan Jia

J. Mar. Sci. Eng. 2020, 8(5), 368; https://doi.org/10.3390/jmse8050368 - 22 May 2020

Cited by 10 | Viewed by 2545

Abstract

Driven by the rapid development of offshore wind farms, bucket foundations have come to constitute a very promising form of foundation for offshore wind turbines, mainly owing to their efficient construction. However, the penetration resistance of the suction penetration of a bucket foundation, [...] Read more.

Driven by the rapid development of offshore wind farms, bucket foundations have come to constitute a very promising form of foundation for offshore wind turbines, mainly owing to their efficient construction. However, the penetration resistance of the suction penetration of a bucket foundation, when calculated inaccurately, may lead to installation failure of the foundation. In this study, model tests were performed on the suction penetration of a mono-bucket mono-compartment foundation and a mono-bucket multi-compartment foundation in saturated fine marine sand, aiming to compare their penetration resistances and critical suctions, and the development of a soil plug in the two models was analyzed. The results will provide a design reference for the penetration construction of bucket foundations for offshore wind turbines. Full article

► Show Figures

Figure 1

24 pages, 369 KiB

Open AccessArticle

Analysis of Operational Efficiency Considering Safety Factors as an Undesirable Output for Coastal Ferry Operators in Korea

by Joohwan Kim, Gunwoo Lee and Hwayoung Kim

J. Mar. Sci. Eng. 2020, 8(5), 367; https://doi.org/10.3390/jmse8050367 - 22 May 2020

Cited by 4 | Viewed by 3074

Abstract

In the maritime transportation services industry, marine accidents may lead to fatalities, injuries, and property losses. Coastal ferry operators experience marine accidents and must pay attention to safety to guarantee the sustainability of their business. This study is aimed at analyzing the operational [...] Read more.

In the maritime transportation services industry, marine accidents may lead to fatalities, injuries, and property losses. Coastal ferry operators experience marine accidents and must pay attention to safety to guarantee the sustainability of their business. This study is aimed at analyzing the operational efficiency of coastal ferry operators in Korea from a safety perspective. We designed two slack-based measure of efficiency (SBM) models. One is a normal SBM, which includes only the total passenger volume as the desirable output. The other is a safety-constrained SBM, which includes marine accident records as an undesirable output with the desirable output of passenger transportation performance. We selected 44 coastal ferry operators in Korea that have been continuously operating for five years (2013–2017) as decision-making units (DMUs) and compared their operational efficiency scores. The results showed that the impact of marine accidents on business is greater in DMUs with lower transportation sales than in those with higher sales. This suggests that, while it is important for the government to strengthen safety regulations, a combination of policies that also help small ferry operators to stay in business in the long term is necessary to reduce marine accidents effectively while improving efficiency. Full article

(This article belongs to the Special Issue Maritime Safety)

14 pages, 1451 KiB

Open AccessArticle

Distributed Ledger Technology as a Tool for Environmental Sustainability in the Shipping Industry

by Srdjan Vujičić, Nermin Hasanspahić, Maro Car and Leo Čampara

J. Mar. Sci. Eng. 2020, 8(5), 366; https://doi.org/10.3390/jmse8050366 - 22 May 2020

Cited by 15 | Viewed by 4471

Abstract

In recent years, many industries have adopted technology and digital systems to automate, expedite and secure specific processes. Stakeholders in maritime transport continue to exchange physical documents in order to conduct business. The monitoring of supply chain goods, communication among employees, environmental sustainability [...] Read more.

In recent years, many industries have adopted technology and digital systems to automate, expedite and secure specific processes. Stakeholders in maritime transport continue to exchange physical documents in order to conduct business. The monitoring of supply chain goods, communication among employees, environmental sustainability and longevity control, along with time framing, all create challenges to many industries. Everyday onboard work, such as cargo operations, navigation and various types of inspections in shipping, still requires paper documents and logs that need to be signed (and stamped). The conversion of traditional paper contracts into smart contracts, which can be digitalized and read through automation, provides a new wave of collaboration between eco systems across the shipping industry. Various data collected and stored on board ships could be used for scientific purposes. Distributed ledger technology (DLT) could be used to collect all those data and improve shipping operations by process expediting. It could eliminate the need to fill in various documents and logs and make operations safer and more environmentally friendly. Information about various important procedures onboard ships could be shared among all interested stakeholders. This paper considers the possible application of distributed ledger technology as an aid for the control of overboard discharge of wastewater from commercial ships. The intended outcome is that it could help protect the environment by sending data to relevant stakeholders in real time, thus providing information regarding the best discharge areas. The use of a structured communal data transference would ensure a consistent and accurate way to transmit data to all interested parties, and would eliminate the need to fill in various paper forms and logs. Wastewater overboard discharges would be properly monitored, recorded and measured, as distributed ledger technology would prevent any possibility of illegal actions and falsification of documents, thus ensuring environmental sustainability. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

20 pages, 6556 KiB

Open AccessArticle

Wind Tunnel Test on the Effect of Solidity on Near Wake Instability of Vertical-Axis Wind Turbine

by Li Zou, Kun Wang, Yichen Jiang, Aimin Wang and Tiezhi Sun

J. Mar. Sci. Eng. 2020, 8(5), 365; https://doi.org/10.3390/jmse8050365 - 22 May 2020

Cited by 6 | Viewed by 2472

Abstract

Owing to the rapid development of the offshore wind power technology and increasing capacity of wind turbines, vertical-axis wind turbines (VAWTs) have experienced a great development. Nevertheless, the VAWT wake effect, which affects the power generation efficiency and rotor fatigue life, has not [...] Read more.

Owing to the rapid development of the offshore wind power technology and increasing capacity of wind turbines, vertical-axis wind turbines (VAWTs) have experienced a great development. Nevertheless, the VAWT wake effect, which affects the power generation efficiency and rotor fatigue life, has not been thoroughly understood. In this study, the mid-span wake measurements on a VAWT in six different configurations were conducted. This study aimed to investigate the effect of solidity on near wake instability of vertical-axis wind turbine. By using the wavelet analysis method to analyse the measured velocity (or pressure) time series signals on a multi-scale and with multi-resolution, the dynamic characteristics of the coherent vortex structures in the wake evolution process were determined. The results show that with increasing solidity, the VAWT wake develops into a bluff body wake mode. In addition, a characteristic frequency that is lower than the low-frequency large-scale vortex shedding frequency occur. The wavelet transform was used to decompose and reconstruct the measured data, and the relationship between the low-frequency large-scale vortex shedding and lower frequency pulsation was established. The results provide important data for numerical modelling and new insights into the physical mechanism of the VAWT wake evolution into a bluff body wake. Full article

(This article belongs to the Special Issue Recent Advances in Fluid Dynamics of Wind and Hydrokinetic Turbines)

► Show Figures

Figure 1

24 pages, 15949 KiB

Open AccessFeature PaperArticle

A UAV-Based Dye-Tracking Technique to Measure Surface Velocities over Tidal Channels and Salt Marshes

by Daniele Pinton, Alberto Canestrelli and Luca Fantuzzi

J. Mar. Sci. Eng. 2020, 8(5), 364; https://doi.org/10.3390/jmse8050364 - 21 May 2020

Cited by 19 | Viewed by 3712

Abstract

An accurate description of hydrodynamic processes in coastal wetlands is needed to improve their management and conservation. As a consequence, higher knowledge of the connected morphological and ecologic processes is achievable. However, it is very costly to collect spatially distributed values of flow [...] Read more.

An accurate description of hydrodynamic processes in coastal wetlands is needed to improve their management and conservation. As a consequence, higher knowledge of the connected morphological and ecologic processes is achievable. However, it is very costly to collect spatially distributed values of flow velocities over tidal channels and intertidal areas by means of in situ sensors. Also, when deploying sensors, humans perturb the ecosystem, which takes time to recover. In this study, a new low-cost unmanned aerial vehicle (UAV)-based method to measure surface velocities is proposed and validated. The study area is a salt marsh system on the southeast coast of Little Sapelo Island, Georgia, USA. Two unmanned aerial vehicles were used in the survey. A first UAV released a fluorescent dye tracer on marshes and tidal creeks, while a second one tracked its movement by collecting RGB images. Flow direction and magnitude were calculated from the images using a newly developed algorithm. A comparison with velocities measured with an acoustic Doppler current profiler confirmed the effectiveness of the method. Our results indicate that the calculated flow field is affected by vegetation, marsh morphology, and marsh width. In particular, a non-negligible velocity component perpendicular to the creek axes is detected both in ebb and in flood. Our technique proves to be an effective, non-intrusive, low-cost way to survey the two-dimensional hydrodynamics on salt marsh environments at a km scale. Collected data would be beneficial for calibrating and validating numerical models with accurate water flux information. Full article

(This article belongs to the Special Issue Advances in Coastal Hydrodynamics and Wetland Modeling)

► Show Figures

Figure 1

14 pages, 4482 KiB

Open AccessArticle

Comparison of Five TRIzol-Based Protein Preparation Methods for 2-DE Production From Challenging Marine Dinoflagellate Samples: A Case Study on Two Benthic Prorocentrum Species

by Thomas Chun-Hung Lee, Kaze King-Yip Lai, Celia Sze-Nga Kwok, Steven Jing-Liang Xu and Fred Wang-Fat Lee

J. Mar. Sci. Eng. 2020, 8(5), 363; https://doi.org/10.3390/jmse8050363 - 21 May 2020

Cited by 3 | Viewed by 3321

Abstract

Two-dimensional gel electrophoresis (2-DE) is a major element of conventional gel-based proteomics, which resolves complex protein mixtures. Protein extraction with the removal of interfering substances from the sample remains the key to producing high-quality 2-DE profiles. Marine dinoflagellates contain large endogenous amounts of [...] Read more.

Two-dimensional gel electrophoresis (2-DE) is a major element of conventional gel-based proteomics, which resolves complex protein mixtures. Protein extraction with the removal of interfering substances from the sample remains the key to producing high-quality 2-DE profiles. Marine dinoflagellates contain large endogenous amounts of salts, nucleic acids, polysaccharides, phenolic compounds, pigments, and other interfering compounds. These substances are detrimental to the quality of gel images. Protein preparation using TRIzol reagent is a promising method for producing high-quality 2-DE profiles for dinoflagellate samples. In addition to its remarkable performance, the TRIzol method’s several advantages have made it a popular and widely used method in the field of 2-DE sample preparation. Nonetheless, the quality of 2-DE of samples from certain dinoflagellate species is not as high as previously reported when the same TRIzol protocol is applied. Therefore, modifications to the original TRIzol method are required to remove interfering substances from those challenging dinoflagellate samples. In this study, the original TRIzol method and four modified methods, namely the aliquot TRIzol method, re-TRIzol method, TRIzol method with a commercial clean-up kit, and TRIzol method with trichloroacetic acid/acetone precipitation, were compared. Performance of these five methods in terms of protein yield, background signal, and resolution and number of protein spots was investigated on samples from two benthic Prorocentrum species: P. lima and P. hoffmannianum. Our results demonstrated that high-quality 2-DE could be achieved from P. lima samples prepared using both the original TRIzol method and the TRIzol method with a commercial clean-up kit. However, the original TRIzol method failed to produce high-quality 2-DE profiles for P. hoffmannianum samples. Among the four modified TRIzol methods, only the TRIzol method with a commercial clean-up kit could yield substantially improved high-quality 2-DE profiles for P. hoffmannianum samples. This combination of the conventional TRIzol method with a commercial clean-up kit potentially represents a promising protein extraction methodology for obtaining high-quality 2-DE profiles for difficult dinoflagellate samples. Full article

(This article belongs to the Special Issue Biocomplexity and Microbial Diversity in a Marine System)

► Show Figures

Figure 1

20 pages, 2926 KiB

Open AccessFeature PaperArticle

Estimation of the Mechanical Recovery Potential of Spilled Oil at Sea Considering the Spatial Thickness Distribution

by Yunseon Choe, Hyeonuk Kim, Cheol Huh, Choong-Ki Kim, Meang-Ik Cho and Hyuek-Jin Choi

J. Mar. Sci. Eng. 2020, 8(5), 362; https://doi.org/10.3390/jmse8050362 - 21 May 2020

Cited by 1 | Viewed by 1878

Abstract

Recovery modeling and countermeasures for oil spilled at sea have been extensively researched, but research remains insufficient on recovery potential estimation methods. It is required to access the mechanical recovery potential by considering the relationship between oil behavior, environmental conditions, and the performance [...] Read more.

Recovery modeling and countermeasures for oil spilled at sea have been extensively researched, but research remains insufficient on recovery potential estimation methods. It is required to access the mechanical recovery potential by considering the relationship between oil behavior, environmental conditions, and the performance of clean-up activities. Two response-planning models were developed in this study. One is a spatially uniform recovery model for estimating recovery potential that reflects weathering, oil properties, and equipment efficiency. The other is a spatially nonuniform recovery model that considers not only the above characteristics but also local thickness reduction by skimming. A comparison between the two models and an analysis of their effects on response was carried out through the calculation using an accident scenario. It is possible to analyze the effect of the thin slicks, natural dissipation, and the quantification of deployable skimming systems with the spatially nonuniform recovery model. Finally, we analyzed interrelationships among residual oil volume on the sea, response time, and the number of skimming systems. Full article

(This article belongs to the Special Issue Advances in Marine Pollution and Disaster)

► Show Figures

Figure 1

17 pages, 8962 KiB

Open AccessFeature PaperArticle

Prediction of Shoreline Evolution. Reliability of a General Model for the Mixed Beach Case

by Giuseppe R. Tomasicchio, Antonio Francone, David J. Simmonds, Felice D’Alessandro and Ferdinando Frega

J. Mar. Sci. Eng. 2020, 8(5), 361; https://doi.org/10.3390/jmse8050361 - 21 May 2020

Cited by 24 | Viewed by 3264

Abstract

In the present paper, after a sensitivity analysis, the calibration and verification of a novel morphodynamic model have been conducted based on a high-quality field experiment data base. The morphodynamic model includes a general formula to predict longshore transport and associated coastal morphology [...] Read more.

In the present paper, after a sensitivity analysis, the calibration and verification of a novel morphodynamic model have been conducted based on a high-quality field experiment data base. The morphodynamic model includes a general formula to predict longshore transport and associated coastal morphology over short- and long-term time scales. With respect to the majority of the existing one-line models, which address sandy coastline evolution, the proposed General Shoreline beach model (GSb) is suitable for estimation of shoreline change at a coastal mound made of non-cohesive sediment grains/units as sand, gravel, cobbles, shingle and rock. In order to verify the reliability of the GSb model, a comparison between observed and calculated shorelines in the presence of a temporary groyne deployed at a mixed beach has been performed. The results show that GSb gives a good agreement between observations and predictions, well reproducing the coastal evolution. Full article

(This article belongs to the Section Coastal Engineering)

► Show Figures

Figure 1

12 pages, 4313 KiB

Open AccessArticle

Experimental Investigation on Small-Strain Stiffness of Marine Silty Sand

by Qi Wu, Qingrui Lu, Qizhou Guo, Kai Zhao, Pen Chen and Guoxing Chen

J. Mar. Sci. Eng. 2020, 8(5), 360; https://doi.org/10.3390/jmse8050360 - 21 May 2020

Cited by 10 | Viewed by 2406

Abstract

The significance of small-strain stiffness (G_max) of saturated composite soils are still of great concern in practice, due to the complex influence of fines on soil fabric. This paper presents an experimental investigation conducted through comprehensive bender element tests on [...] Read more.

The significance of small-strain stiffness (G_max) of saturated composite soils are still of great concern in practice, due to the complex influence of fines on soil fabric. This paper presents an experimental investigation conducted through comprehensive bender element tests on G_max of marine silty sand. Special attention is paid to the influence of initial effective confining pressure (

σ_{c 0}^{'}

), global void ratio (e) and fines content (FC) on G_max of a marine silty sand. The results indicate that under otherwise similar conditions, G_max decreases with decreasing e or FC, but decreases with increasing FC. In addition, the reduction rate of G_max with e increasing is not sensitive to

σ_{c 0}^{'}

, but obviously sensitive to changes in FC. The equivalent skeleton void ratio (e*) is introduced as an alternative state index for silty sand with various FC, based on the concept of binary packing material. Remarkably, the Hardin model is modified with the new state index e*, allowing unified characterization of G_max values for silty sand with various FC, e, and

σ_{c 0}^{'}

. Independent test data for different silty sand published in the literature calibrate the applicability of this proposed model. Full article

(This article belongs to the Special Issue New Advances in Marine Engineering Geology)

► Show Figures

Figure 1

14 pages, 11055 KiB

Open AccessArticle

Cathodic Protection of A Container Ship Using A Detailed BEM Model

by Dimitrios T. Kalovelonis, Dimitrios C. Rodopoulos, Theodoros V. Gortsas, Demosthenes Polyzos and Stephanos V. Tsinopoulos

J. Mar. Sci. Eng. 2020, 8(5), 359; https://doi.org/10.3390/jmse8050359 - 20 May 2020

Cited by 17 | Viewed by 4322

Abstract

In the present work, an impressed current cathodic protection (ICCP) system for the protection against corrosion of a 399-m-length container ship throughout its service life is designed. The study is carried out with the aid of a boundary element method code, accelerated by [...] Read more.

In the present work, an impressed current cathodic protection (ICCP) system for the protection against corrosion of a 399-m-length container ship throughout its service life is designed. The study is carried out with the aid of a boundary element method code, accelerated by an adaptive cross approximation scheme, utilizing a detailed large-scale model. The exact geometry of the ship, the progressive damage of the coating system, and the dynamic state during the cruise of the ship are the main parameters taken into consideration in modelling. The main objective of the design process is to minimize the electric power, delivered by the ICCP system, determining the optimal number and location of the installed inert anodes to accomplish the absolute minimum protection potential on the immersed steel surfaces of the ship and, simultaneously, avoid overprotection. Performing an extensive parametric study, a six-zone ICCP system is proposed, consisting of 10 anodes at the hull and four identical anodes at each of four thrusters. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

15 pages, 4098 KiB

Open AccessArticle

Long-Term Performance of Trestle Bridges: Case Study of an Indonesian Marine Port Structure

by Yusak Oktavianus, Massoud Sofi, Elisa Lumantarna, Gideon Kusuma and Colin Duffield

J. Mar. Sci. Eng. 2020, 8(5), 358; https://doi.org/10.3390/jmse8050358 - 19 May 2020

Cited by 10 | Viewed by 2813

Abstract

A precast reinforced concrete (RC) T-beam located in seaport Terminal Peti Kemas (TPS) Surabaya built in 1984 is used as a case study to test the accuracy of non-destructive test techniques against more traditional bridge evaluation tools. This bridge is mainly used to [...] Read more.

A precast reinforced concrete (RC) T-beam located in seaport Terminal Peti Kemas (TPS) Surabaya built in 1984 is used as a case study to test the accuracy of non-destructive test techniques against more traditional bridge evaluation tools. This bridge is mainly used to connect the berth in Lamong gulf and the port in Java Island for the logistic purposes. The bridge was retrofitted 26 years into its life by adding two strips of carbon fiber reinforced polymer (CFRP) due to excessive cracks observed in the beams. Non-destructive field measurements were compared against a detailed finite element analysis of the structure to predict the performance of the girder in terms of deflection and moment capacity before and after the retrofitting work. The analysis was also used to predict the long-term deflections of the structure due to creep, crack distribution, and the ultimate moment capacity of the individual girder. Moreover, the finite element analysis was used to predict the deflection behavior of the overall bridge due to vehicle loading. Good agreement was obtained between the field measurement and the analytical study. A new service life of the structure considering the corrosion and new vehicle demand is carried out based on field measurement using non-destructive testing. Not only are the specific results beneficial for the Indonesian port authority as the stakeholder to manage this structure, but the approach detailed also paves the way for more efficient evaluation of bridges more generally over their service life. Full article

(This article belongs to the Special Issue Sustainable Concrete in the Marine Environment)

► Show Figures

Figure 1

32 pages, 9964 KiB

Open AccessFeature PaperArticle

Free-Surface Effects on the Performance of Flapping-Foil Thruster for Augmenting Ship Propulsion in Waves

by Evangelos S. Filippas, George P. Papadakis and Kostas A. Belibassakis

J. Mar. Sci. Eng. 2020, 8(5), 357; https://doi.org/10.3390/jmse8050357 - 19 May 2020

Cited by 27 | Viewed by 3258

Abstract

Flapping foils located beneath or to the side of the hull of the ship can be used as unsteady thrusters, augmenting ship propulsion in waves. The basic setup is composed of a horizontal wing, which undergoes an induced vertical motion due to the [...] Read more.

Flapping foils located beneath or to the side of the hull of the ship can be used as unsteady thrusters, augmenting ship propulsion in waves. The basic setup is composed of a horizontal wing, which undergoes an induced vertical motion due to the ship’s responses in waves, while the self-pitching motion of the wing is controlled. Flapping foil thrusters can achieve high level of thrust as indicated by measurements and numerical simulations. Due to the relatively small submergence of the above biomimetic ship thrusters, the free-surface effects become significant. In the present work, the effect of the free surface on the performance of flapping foil thruster is assessed by means of two in-house developed computational models. On one hand, a cost-effective time-domain boundary element method (BEM) solver exploiting parallel programming techniques and general purpose programming on graphics processing units (GPGPU) is employed, while on the other hand a higher fidelity RANSE finite volume solver implemented for high performance computing (HPC) is used, and comparative results are presented. BEM and RANSE calculations present quite similar trends with respect to mean submergence depth, presenting 12%, 28%, and 18% of differences concerning the mean values of lift, thrust, and moment coefficients, respectively. The latter differences become very small after enhancement of the BEM model to include viscous corrections. Useful information and data are derived supporting the design of the considered biomimetic thrusters, for moderate submergence depths and conditions characterized by minor flow separation effects. Full article

(This article belongs to the Special Issue Propulsion of Ships in Waves)

► Show Figures

Figure 1

17 pages, 6139 KiB

Open AccessArticle

A Novel Vision-Based Towing Angle Estimation for Maritime Towing Operations

by Xiong Zou, Wenqiang Zhan, Changshi Xiao, Chunhui Zhou, Qianqian Chen, Tiantian Yang and Xin Liu

J. Mar. Sci. Eng. 2020, 8(5), 356; https://doi.org/10.3390/jmse8050356 - 18 May 2020

Cited by 3 | Viewed by 2125

Abstract

The demand for non-powered facility towing is increasing with the development of large-scale offshore projects. It is of great interest for its safe operation to measure the state of the towing process in real time. This paper proposed a computer vision algorithm designed [...] Read more.

The demand for non-powered facility towing is increasing with the development of large-scale offshore projects. It is of great interest for its safe operation to measure the state of the towing process in real time. This paper proposed a computer vision algorithm designed to measure the tug yawing during the towing operation by estimating the towing line angle. The geometrical projection of the towing line from 3D to 2D is described in detail. By fixing the camera at specific locations and simplifying the calculation procedure, the towing line angle in the 3D world can be estimated by the line angle in the image. Firstly, the sea–sky line is detected to estimate the rolling angle of the tug in the captured image. Then, the towing line angle is calculated by an image processing method. At the same time, the estimation of the towing angle is achieved through the captured video data analysis. Finally, field experiments were carried out and the results demonstrated that this method is suitable for real-time calculation of the towing angle during the towing operation. Full article

(This article belongs to the Special Issue Maritime Safety)

► Show Figures

Figure 1

26 pages, 3285 KiB

Open AccessArticle

Viscous Damping Identification for a Wave Energy Converter Using CFD-URANS Simulations

by Marco Fontana, Pietro Casalone, Sergej Antonello Sirigu, Giuseppe Giorgi, Giovanni Bracco and Giuliana Mattiazzo

J. Mar. Sci. Eng. 2020, 8(5), 355; https://doi.org/10.3390/jmse8050355 - 17 May 2020

Cited by 31 | Viewed by 3071

Abstract

During the optimization phase of a wave energy converter (WEC), it is essential to be able to rely on a model that is both fast and accurate. In this regard, Computational Fluid Dynamic (CFD) with Reynolds Averaged Navier–Stokes (RANS) approach is not suitable [...] Read more.

During the optimization phase of a wave energy converter (WEC), it is essential to be able to rely on a model that is both fast and accurate. In this regard, Computational Fluid Dynamic (CFD) with Reynolds Averaged Navier–Stokes (RANS) approach is not suitable for optimization studies, given its computational cost, while methods based on potential theory are fast but not accurate enough. A good compromise can be found in boundary element methods (BEMs), based on potential theory, with the addition of non-linearities. This paper deals with the identification of viscous parameters to account for such non-linearities, based on CFD-Unsteady RANS (URANS) analysis. The work proposes two different methodologies to identify the viscous damping along the rotational degree of freedom (DOF) of pitch and roll: The first solely involves the outcomes of the CFD simulations, computing the viscous damping coefficients through the logarithmic decrement method, the second approach solves the Cummins’ equation of motion, via a Runge-Kutta scheme, selecting the damping coefficients that minimize the difference with CFD time series. The viscous damping is mostly linear for pitch and quadratic for roll, given the shape of the WEC analysed. Full article

(This article belongs to the Special Issue CFD Simulations of Marine Hydrodynamics)

► Show Figures

Figure 1

18 pages, 4645 KiB

Open AccessArticle

Path Following of a Water-Jetted USV Based on Maneuverability Tests

by Junmin Mou, Yangying He, Benren Zhang, Shixuan Li and Yong Xiong

J. Mar. Sci. Eng. 2020, 8(5), 354; https://doi.org/10.3390/jmse8050354 - 16 May 2020

Cited by 13 | Viewed by 3160

Abstract

Due to the high propulsive efficiency and better maneuverability under high speed, the water-jetted unmanned surface vehicle (USV) is widely studied and used. This paper presents complete maneuvering tests and control algorithm designed for a twin water-jetted USV model. Firstly, a wireless network [...] Read more.

Due to the high propulsive efficiency and better maneuverability under high speed, the water-jetted unmanned surface vehicle (USV) is widely studied and used. This paper presents complete maneuvering tests and control algorithm designed for a twin water-jetted USV model. Firstly, a wireless network control platform is established, and maneuvering tests, for instance, an inertia test, zig-zag test and turning test, are carried out to verify the maneuverability of the USV. In light of the complexity and uncertainty of ship sailing and ship handling, the Human Simulated Intelligent Control (HSIC) method is utilized to optimize the response time, accuracy and robustness of the controller. Finally, for the path following and track rectification part, a Line of Sight (LOS) algorithm is improved and proved practicable with triangle/square path tests. The proposed intelligent navigation algorithm specially designed for matching with the control methods, showing satisfactory improvements on the motion control and path following of the specific USV. Full article

(This article belongs to the Special Issue Unmanned Marine Vehicles)

► Show Figures

Figure 1

15 pages, 6673 KiB

Open AccessArticle

Optimum Arrangement Design of Mastic Ropes for Membrane-Type LNG Tanks Considering the Flatness of Thermal Insulation Panel and Production Cost

by Do-Hyun Chun, Myung-Il Roh and Seung-Ho Ham

J. Mar. Sci. Eng. 2020, 8(5), 353; https://doi.org/10.3390/jmse8050353 - 16 May 2020

Cited by 4 | Viewed by 3022

Abstract

Thermal insulation panels are installed on the inner walls of liquefied natural gas (LNG) tanks of an LNG carrier to maintain the cryogenic temperature. Mastic ropes are used to attach thermal insulation panels to the inner walls and to fill the gap between [...] Read more.

Thermal insulation panels are installed on the inner walls of liquefied natural gas (LNG) tanks of an LNG carrier to maintain the cryogenic temperature. Mastic ropes are used to attach thermal insulation panels to the inner walls and to fill the gap between the walls and panels. Because the inner walls of the LNG tanks can be corrugated owing to production errors, a large amount of mastic ropes are required to maintain the flatness of the thermal insulation panels. Therefore, in this study, an optimization method is proposed to minimize the total amount of mastic ropes for satisfying the flatness criterion of thermal insulation panels. For this purpose, an optimization problem is mathematically formulated. An objective function is used to minimize the total amount of mastic ropes considering constraints to flatten the thermal insulation panels. This function is applied to the design of membrane-type LNG tanks to verify the effectiveness and feasibility of the proposed method. Consequently, we confirm that the proposed method can provide a more effective arrangement design of mastic ropes compared with manual design. Full article

(This article belongs to the Special Issue Computer-Aided Marine Structures’ Design)

► Show Figures

Graphical abstract

15 pages, 5313 KiB

Open AccessArticle

Wave Load Mitigation by Perforation of Monopiles

by Jacob Andersen, Rune Abrahamsen, Thomas Lykke Andersen, Morten Thøtt Andersen, Torben Ladegaard Baun and Jesper Lykkegaard Neubauer

J. Mar. Sci. Eng. 2020, 8(5), 352; https://doi.org/10.3390/jmse8050352 - 16 May 2020

Viewed by 2167

Abstract

The design of large diameter monopiles (8–10 m) at intermediate to deep waters is largely driven by the fatigue limit state and mainly due to wave loads. The scope of the present paper is to assess the mitigation of wave loads on a [...] Read more.

The design of large diameter monopiles (8–10 m) at intermediate to deep waters is largely driven by the fatigue limit state and mainly due to wave loads. The scope of the present paper is to assess the mitigation of wave loads on a monopile by perforation of the shell. The perforation design consists of elliptical holes in the vicinity of the splash zone. Wave loads are estimated for both regular and irregular waves through physical model tests in a wave flume. The test matrix includes waves with Keulegan–Carpenter (

K C

) numbers in the range 0.25 to 10 and covers both fatigue and ultimate limit states. Load reductions in the order of 6%–20% are found for

K C

numbers above 1.5. Significantly higher load reductions are found for

K C

numbers less than 1.5 and thus the potential to reduce fatigue wave loads has been demonstrated. Full article

(This article belongs to the Section Ocean Engineering)

► Show Figures

Figure 1

19 pages, 8119 KiB

Open AccessArticle

Thermo-Economic Performance of an Organic Rankine Cycle System Recovering Waste Heat Onboard an Offshore Service Vessel

by ChunWee Ng, Ivan C. K. Tam and Dawei Wu

J. Mar. Sci. Eng. 2020, 8(5), 351; https://doi.org/10.3390/jmse8050351 - 14 May 2020

Cited by 12 | Viewed by 2857

Abstract

Recent regulatory developments in the global maritime industry have signalled an increased emphasis on the improvement of energy efficiency onboard ships. Among the various efficiency enhancement options, recovering waste heat using the organic Rankine cycle (ORC) has been studied and identified as a [...] Read more.

Recent regulatory developments in the global maritime industry have signalled an increased emphasis on the improvement of energy efficiency onboard ships. Among the various efficiency enhancement options, recovering waste heat using the organic Rankine cycle (ORC) has been studied and identified as a promising one in many earlier studies. In this paper, a marine application of ORC for waste heat recovery will be discussed by performing the first law thermodynamic analysis based on the operating profile and machinery design data of an offshore service vessel (OSV) and defining four standard cycle configurations that include simple, recuperated, dual heat source, and with intermediate heating. The use of five hydrocarbon working fluids that are suitable for shipboard usage comprising cyclopentane, n-heptane, n-octane, methanol and ethanol are examined. The economic analysis found that annual fuel saving between 5% and 9% is possible and estimated a specific installation cost of $5000–8000 USD/kW. Among the various options, the methanol ORC in a simple cycle configuration is found to have the shortest payback time relatively balancing between annual fuel saving and total module cost. Finally, the simple cycle ORC running on methanol is further examined using the second law entropy generation analysis and it is found that the heat exchangers in the system accounted for nearly 95% of the overall entropy generation rate and further work is recommended to reduce this in the future. Full article

(This article belongs to the Special Issue Solutions for Reducing the Environmental Impact of Marine Energy Systems)

► Show Figures

Figure 1

13 pages, 2005 KiB

Open AccessArticle

Approaching Software Engineering for Marine Sciences: A Single Development Process for Multiple End-User Applications

by Pedro Magaña, Juan Del-Rosal-Salido, Manuel Cobos, Andrea Lira-Loarca and Miguel Ortega-Sánchez

J. Mar. Sci. Eng. 2020, 8(5), 350; https://doi.org/10.3390/jmse8050350 - 14 May 2020

Cited by 2 | Viewed by 2147

Abstract

Research software is currently used by a large number of scientists on a daily basis, and everything indicates that this trend will continue to increase in the future. Most of this scientific software is very often developed by the researchers themselves, who usually [...] Read more.

Research software is currently used by a large number of scientists on a daily basis, and everything indicates that this trend will continue to increase in the future. Most of this scientific software is very often developed by the researchers themselves, who usually make it available to the rest of the scientific community. Although the relationship between science and software is unquestionably useful, it is not always successful. Some of the critical problems that scientists face include a lack of training in software development, a shortage of time and resources, or difficulty in effectively cooperating with other colleagues. Additional challenges arise in the context of increasingly common cross-cutting and multidisciplinary research. This often results in the developed software and code being slow, not reusable, lacks visibility and dissemination, and in the worst cases it is defective and unreliable. Therefore, a multidisciplinary framework is needed to meet the demands of both scientists and software engineers and handle the situation successfully. However, a multidisciplinary team is not always sufficient to solve this problem, and it is necessary to have links between scientists and developers: software engineers with a solid scientific background. This paper presents the approach used in the framework of the PROTOCOL project, and more particularly in the development of its applied software, in which a tool for the characterization of climate agents has been developed. The main guidelines of the development process include, among others, modularity, distributed control version, unit testing, profiling, inline documentation and the use of best practices and tools. Full article

(This article belongs to the Special Issue Selected Papers from the Spanish Days of Ports and Coasts)

► Show Figures

Figure 1

Journal Menu

Journal Browser

J. Mar. Sci. Eng., Volume 8, Issue 5 (May 2020) – 80 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI