Mahmoud Abdelnaser Saadeldin, M. M. Elgoharya, Maged Abdelnaby, M. Shouman
{"title":"Effects of Direct Water Injection on the Nitrogen Oxide Emission Characteristics of Marine Diesel Engines","authors":"Mahmoud Abdelnaser Saadeldin, M. M. Elgoharya, Maged Abdelnaby, M. Shouman","doi":"10.51400/2709-6998.2692","DOIUrl":"https://doi.org/10.51400/2709-6998.2692","url":null,"abstract":"","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45787938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.1007/s00773-022-00909-2
P. Bo, Xingbin Tu, Yan Wei, Fengzhong Qu
{"title":"Anti-disturbance depth control based on the robust $$L_{1}$$ filter for under-actuated AUV with switched linear parameter varying dynamics","authors":"P. Bo, Xingbin Tu, Yan Wei, Fengzhong Qu","doi":"10.1007/s00773-022-00909-2","DOIUrl":"https://doi.org/10.1007/s00773-022-00909-2","url":null,"abstract":"","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47517537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-23DOI: 10.1007/s00773-022-00916-3
M. Abbaszadeh, M. Alishahi
{"title":"A coupled experimental and numerical investigation of the bubbly wake of a ship model in towing tank","authors":"M. Abbaszadeh, M. Alishahi","doi":"10.1007/s00773-022-00916-3","DOIUrl":"https://doi.org/10.1007/s00773-022-00916-3","url":null,"abstract":"","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":"28 1","pages":"165 - 178"},"PeriodicalIF":0.5,"publicationDate":"2022-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49444824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-19DOI: 10.1007/s00773-023-00950-9
D. M. Rachman, Y. Aoki, Yoshiki Miyauchi, N. Umeda, A. Maki
{"title":"Experimental low-speed positioning system with VecTwin rudder for automatic docking (berthing)","authors":"D. M. Rachman, Y. Aoki, Yoshiki Miyauchi, N. Umeda, A. Maki","doi":"10.1007/s00773-023-00950-9","DOIUrl":"https://doi.org/10.1007/s00773-023-00950-9","url":null,"abstract":"","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":"28 1","pages":"689 - 703"},"PeriodicalIF":0.5,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45355598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A noise abatement method using an eigen function in conjunction with an optimizer (Genetic Algorithm) under a space-constrain situation is proposed in this study concerning a high order wave propagation effect. An eigen function is used to describe an acoustical field and shorten the acoustical model in a four-pole transfer matrix form. The system's four-pole matrix estimates the Transmission Loss (TL) for the silencers by multiplying individual four-pole matrices. Additionally, a case studyof an air compressor's broadbandnoise elimination is introduced.Three types of circular reverse silencers (silencers A-C) internally hybridized with multiple straight chambers are adopted to efficiently suppress the noise wave. Considering broadband characteristics and space-constrained situations, an average-deviation-integrating form used as an objective function is presented and linked to anoptimizer-GA (GeneticAlgorithm).Acousticalmodels for silencersA to C are checkedbefore the numerical optimization is performed.Apure toneoptimization is executed to assure the consistency of the GA scheme. The result shows that the overall noise drop is enhanced and the number of straight expansion chambers installed at the inlet/outlet of the circular reverse silencer increases. Consequently, concerning a space-constrained situation in the real world and the characteristics of the broadband noise spectrum, an efficient method is proposed in this paper for designing an optimally shaped hybrid muffler using the objective function in conjunction with an optimization scheme.
{"title":"Optimization of Circular Silencers Internally Hybridized with Multiple Reverse Chambers Using the GA Method","authors":"M. Chiu, Ying-Chun Chang, T. Lan, Ho-Sheng Chen","doi":"10.51400/2709-6998.2587","DOIUrl":"https://doi.org/10.51400/2709-6998.2587","url":null,"abstract":"A noise abatement method using an eigen function in conjunction with an optimizer (Genetic Algorithm) under a space-constrain situation is proposed in this study concerning a high order wave propagation effect. An eigen function is used to describe an acoustical field and shorten the acoustical model in a four-pole transfer matrix form. The system's four-pole matrix estimates the Transmission Loss (TL) for the silencers by multiplying individual four-pole matrices. Additionally, a case studyof an air compressor's broadbandnoise elimination is introduced.Three types of circular reverse silencers (silencers A-C) internally hybridized with multiple straight chambers are adopted to efficiently suppress the noise wave. Considering broadband characteristics and space-constrained situations, an average-deviation-integrating form used as an objective function is presented and linked to anoptimizer-GA (GeneticAlgorithm).Acousticalmodels for silencersA to C are checkedbefore the numerical optimization is performed.Apure toneoptimization is executed to assure the consistency of the GA scheme. The result shows that the overall noise drop is enhanced and the number of straight expansion chambers installed at the inlet/outlet of the circular reverse silencer increases. Consequently, concerning a space-constrained situation in the real world and the characteristics of the broadband noise spectrum, an efficient method is proposed in this paper for designing an optimally shaped hybrid muffler using the objective function in conjunction with an optimization scheme.","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44993692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The grounding accident of M/V EVER GIVEN in the Suez Canal causes a catastrophic loss on shipping companies. Alternatively, previous studies have presented encouraging fi ndings of the remarkable bene fi ts of time and cost saving in the Northern sea route (NSR) due to extend the ice-free time and shorten the distance. Ships using the NSR could shorten as much as 40% of the sailing distance from China (Shanghai) to Europe (Rotterdam) compared with the traditional route via the Suez Canal. This paper investigates the economic potential of using the NSR as a cost-effective route in comparison with Suez Canal Route (SCR) between China and Europe. To achieve this target, the study evaluates the net pro fi t for the SCR fl eet and NSR fl eet by involving the factors, e.g., bunker price, ice condition and ship loading rate, etc. The case-study results show that the NSR fl eet is not pro fi table compared to the SCR, due to the limited cargo transport capability and ice restriction. Only if the loading rate for SCR fl eet is lower than some threshold value or the bunker price is high enough, the NSR turns to be pro fi table.
{"title":"Performance Analysis: Using the Northern Sea Route as an Alternative to Traditional Routes","authors":"Liangkun Xu, Qing Yu","doi":"10.51400/2709-6998.2591","DOIUrl":"https://doi.org/10.51400/2709-6998.2591","url":null,"abstract":"The grounding accident of M/V EVER GIVEN in the Suez Canal causes a catastrophic loss on shipping companies. Alternatively, previous studies have presented encouraging fi ndings of the remarkable bene fi ts of time and cost saving in the Northern sea route (NSR) due to extend the ice-free time and shorten the distance. Ships using the NSR could shorten as much as 40% of the sailing distance from China (Shanghai) to Europe (Rotterdam) compared with the traditional route via the Suez Canal. This paper investigates the economic potential of using the NSR as a cost-effective route in comparison with Suez Canal Route (SCR) between China and Europe. To achieve this target, the study evaluates the net pro fi t for the SCR fl eet and NSR fl eet by involving the factors, e.g., bunker price, ice condition and ship loading rate, etc. The case-study results show that the NSR fl eet is not pro fi table compared to the SCR, due to the limited cargo transport capability and ice restriction. Only if the loading rate for SCR fl eet is lower than some threshold value or the bunker price is high enough, the NSR turns to be pro fi table.","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45762843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper considers the second-order nonlinear boundary value problem (NBVP), which is equipped with nonlinear integral boundary conditions (BCs). Two novel iterative algorithms are developed to overcome the difficulty of NBVP with double nonlinearities involved. In the first iterative algorithm, two nonlocal shape functions incorporating the linear integral terms are derived, and a nonlocal boundary shape function (NBSF) is formulated to assist the solution. Let the solution be the NBSF so that the NBVP can be exactly transformed into an initial value problem. The new variable is a free function in the NBSF, and its initial values are given. For the NBVP with linear integral BCs, three unknown constants are to be determined, while for the nonlinear integral BCs, five unknown constants are to be determined. Twopoint local shape functions and local boundary shape functions are derived for the second iterative algorithm, wherein the integral terms in the boundary conditions are viewed as unknown constants. By a few iterations, four unknown constants can be determined quickly. Through numerical experiments, these two iterative algorithms are found to be powerful for seeking quite accurate solutions. The second algorithm is slightly better than the first, with fewer iterations and a more accurate solution.
{"title":"Solving Nonlinear Boundary Value Problems with Nonlinear Integral Boundary Conditions by Local and Nonlocal Boundary Shape Functions Methods","authors":"Chein-Shan Liu, Yung-Wei Chen, Jian-Hung Shen","doi":"10.51400/2709-6998.2581","DOIUrl":"https://doi.org/10.51400/2709-6998.2581","url":null,"abstract":"The paper considers the second-order nonlinear boundary value problem (NBVP), which is equipped with nonlinear integral boundary conditions (BCs). Two novel iterative algorithms are developed to overcome the difficulty of NBVP with double nonlinearities involved. In the first iterative algorithm, two nonlocal shape functions incorporating the linear integral terms are derived, and a nonlocal boundary shape function (NBSF) is formulated to assist the solution. Let the solution be the NBSF so that the NBVP can be exactly transformed into an initial value problem. The new variable is a free function in the NBSF, and its initial values are given. For the NBVP with linear integral BCs, three unknown constants are to be determined, while for the nonlinear integral BCs, five unknown constants are to be determined. Twopoint local shape functions and local boundary shape functions are derived for the second iterative algorithm, wherein the integral terms in the boundary conditions are viewed as unknown constants. By a few iterations, four unknown constants can be determined quickly. Through numerical experiments, these two iterative algorithms are found to be powerful for seeking quite accurate solutions. The second algorithm is slightly better than the first, with fewer iterations and a more accurate solution.","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43180188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine debris is a global problem that has not been resolved. This has encouraged the emergence of marine debris cleaning technologies, one of which is a conveyor ship. However, how effective conveyors are in collecting waste has not been studied. In this paper, experimental research on conveyors as marine debris collectors is investigated. The capability of catamarans with or without solid wing conveyors to collect marine debris is explored. Three kinds of marine debris collection models are used: no-wing conveyor, a 12.5-cm-long wing conveyor, and an 18.75-cm-long wing conveyor. Artificial marine debris (AMD) is spread on the water surface in a static tank. Then, a marine debris collector model is pulled using threads tied to the ship's body. This is done several times starting from a low speed and progressing to a high speed. After the experiment, the effectiveness of marine debris collection from these three models is analysed. In addition, the cause of marine debris not being caught by the model is investigated. This work proposes a new approach to evaluate the effectiveness of conveyer wings in marine debris collection. Based on AMD movement pattern analysis, it is suggested to operate the device at a low speed because the collected AMD ratio is high and the lost
{"title":"Experimental Study of the Effect of a Solid Wing Conveyor on Marine Debris Collection","authors":"E. Sugianto, Jeng-Horng Chen","doi":"10.51400/2709-6998.2584","DOIUrl":"https://doi.org/10.51400/2709-6998.2584","url":null,"abstract":"Marine debris is a global problem that has not been resolved. This has encouraged the emergence of marine debris cleaning technologies, one of which is a conveyor ship. However, how effective conveyors are in collecting waste has not been studied. In this paper, experimental research on conveyors as marine debris collectors is investigated. The capability of catamarans with or without solid wing conveyors to collect marine debris is explored. Three kinds of marine debris collection models are used: no-wing conveyor, a 12.5-cm-long wing conveyor, and an 18.75-cm-long wing conveyor. Artificial marine debris (AMD) is spread on the water surface in a static tank. Then, a marine debris collector model is pulled using threads tied to the ship's body. This is done several times starting from a low speed and progressing to a high speed. After the experiment, the effectiveness of marine debris collection from these three models is analysed. In addition, the cause of marine debris not being caught by the model is investigated. This work proposes a new approach to evaluate the effectiveness of conveyer wings in marine debris collection. Based on AMD movement pattern analysis, it is suggested to operate the device at a low speed because the collected AMD ratio is high and the lost","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42983633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study was to identify the sources of uncertainties of typhoon wave field monitoring using HF radar and to quantitatively assess the bias of the wave parameters, such as significant wave height and mean period, retrieved under various conditions. The strategy was to apply a purely numerical simulation of the Doppler-range spectra and then compare the estimation results to the target. For the quantitative investigation, a numerical test-bed was established. The test-bed was used to simulate the Doppler spectra based on Barrick's (1972) theory by using the input of the directional wave spectra. The typhoon wave spectra were hindcasted using a third-generation wave model. Initially, the uncertainty source from Barrick's theory was identified when comparing the deviations of the estimation results obtained from the idealized case of steady and homogenous fields. The accuracy of the wave height and the mean period was found to be significantly influenced by the angle between the radar-looking direction and the wave direction. Furthermore, two conceptual numerical experiments were designed to evaluate the uncertainties owing to the rotation and the translation of the typhoon wind fields, respectively. The first design focussed on the upper-right quadrant around the maximum wind radius of the typhoon using a virtual radar network that moved along with the typhoon. The second one was a more realistic design in that the virtual radar stations were located on the coastline. The scatter index of the wave height estimated from the second design was found to be approximately twice larger than that obtained using the first design. It was 25% larger for the uncertainty of the mean period. This demonstrated that except for the error from theory, the uncertainty of the estimated wave parameters in type 1 was influenced by the change in the wave generated by the wind field, while that of type 2 was affected by the complicated typhoon wavefield, including the mixed wind waves and swells. The results showed that the error of 0.02 of the scatter index in the case of the wave height could be identified even when no system noise was considered. This error was attributed to the simplification of the coupling coefficient and the weighting function in Barrick's theory. The error was direction dependent and non-negligible. For the typhoon cases, the heterogeneity and rapid changes in the spatial distribution of the wavefield under the influence of the rotating wind fields were the challenging factors for the HF radar wave parameter retrieval. The error increased further under such conditions.
{"title":"Numerical Investigation Of The Uncertainty Of Typhoon Wave Parameters Retrieval Using HF Radar","authors":"T. Dao, Hwa Chien","doi":"10.51400/2709-6998.2586","DOIUrl":"https://doi.org/10.51400/2709-6998.2586","url":null,"abstract":"The aim of this study was to identify the sources of uncertainties of typhoon wave field monitoring using HF radar and to quantitatively assess the bias of the wave parameters, such as significant wave height and mean period, retrieved under various conditions. The strategy was to apply a purely numerical simulation of the Doppler-range spectra and then compare the estimation results to the target. For the quantitative investigation, a numerical test-bed was established. The test-bed was used to simulate the Doppler spectra based on Barrick's (1972) theory by using the input of the directional wave spectra. The typhoon wave spectra were hindcasted using a third-generation wave model. Initially, the uncertainty source from Barrick's theory was identified when comparing the deviations of the estimation results obtained from the idealized case of steady and homogenous fields. The accuracy of the wave height and the mean period was found to be significantly influenced by the angle between the radar-looking direction and the wave direction. Furthermore, two conceptual numerical experiments were designed to evaluate the uncertainties owing to the rotation and the translation of the typhoon wind fields, respectively. The first design focussed on the upper-right quadrant around the maximum wind radius of the typhoon using a virtual radar network that moved along with the typhoon. The second one was a more realistic design in that the virtual radar stations were located on the coastline. The scatter index of the wave height estimated from the second design was found to be approximately twice larger than that obtained using the first design. It was 25% larger for the uncertainty of the mean period. This demonstrated that except for the error from theory, the uncertainty of the estimated wave parameters in type 1 was influenced by the change in the wave generated by the wind field, while that of type 2 was affected by the complicated typhoon wavefield, including the mixed wind waves and swells. The results showed that the error of 0.02 of the scatter index in the case of the wave height could be identified even when no system noise was considered. This error was attributed to the simplification of the coupling coefficient and the weighting function in Barrick's theory. The error was direction dependent and non-negligible. For the typhoon cases, the heterogeneity and rapid changes in the spatial distribution of the wavefield under the influence of the rotating wind fields were the challenging factors for the HF radar wave parameter retrieval. The error increased further under such conditions.","PeriodicalId":50149,"journal":{"name":"Journal of Marine Science and Technology-Taiwan","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43472507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}