Brodogradnja最新文献_第2页

Study on the relationship between tsunami waves in dam break state and initial water levels 溃坝状态海啸波与初始水位关系的研究

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-09-01 DOI: 10.21278/brod74405

Xiaohe Lai, Xin Deng, Cheng Chen, Chen Peng, Zixuan Li, Haoyan Chen

{"title":"Study on the relationship between tsunami waves in dam break state and initial water levels","authors":"Xiaohe Lai, Xin Deng, Cheng Chen, Chen Peng, Zixuan Li, Haoyan Chen","doi":"10.21278/brod74405","DOIUrl":"https://doi.org/10.21278/brod74405","url":null,"abstract":"Tsunami wave characteristics are greatly influenced by the initial water level when they attack structures. In this study, experimental and numerical investigations were conducted to investigated the relationship between tsunami wave characteristics and initial water levels. Results showed that, the wave height, wave velocity, and Froude number increase with the increase of tsunami wave intensity; the time history of water levels were influenced by the different initial water level conditions; the analytical solution proposed by Chanson (2005) may be extended to wet-bed conditions (for initial water level < 0.36 tsunami bore height in our experimental set-up). Due to the limitations of experimental ranges in the laboratory, the validated numerical model can provide more results for wider experimental ranges for tsunami bore investigations. It was observed from numerical results that, tsunami bore height increases with the increase of reservoir water level; tsunami bore velocity decreases with the increased initial water level on the bed; as the initial water level on the bed gradually increases, the mean tsunami bore Froude number shows a downward trend.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42753237","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}

引用次数: 0

Numerical investigation of multi-nozzle ejector device with inclined nozzles for marine gas turbine 船用燃气轮机倾斜喷嘴多喷嘴喷射器的数值研究

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-09-01 DOI: 10.21278/brod74401

Hong Shi, Rentong Zheng, Qianwei Zhang, Jie Yuan, Rui Wang, Mengmeng Cheng, Yitao Zou

{"title":"Numerical investigation of multi-nozzle ejector device with inclined nozzles for marine gas turbine","authors":"Hong Shi, Rentong Zheng, Qianwei Zhang, Jie Yuan, Rui Wang, Mengmeng Cheng, Yitao Zou","doi":"10.21278/brod74401","DOIUrl":"https://doi.org/10.21278/brod74401","url":null,"abstract":"The high-temperature exhaust gases and the hot surfaces of the ejector device in marine gas turbines generate significant levels of infrared radiation. An appropriate nozzle structure can effectively lower the exhaust gas temperature and reduce the high-temperature radiation surface area, thereby minimizing external infrared radiation. In this study, a numerical simulation of the nozzle structure in the ejector device was conducted using computational fluid dynamics (CFD) methods. By investigating the orthogonal combinations of nozzle inclination angles and the number of nozzles, the temperature distribution and flow characteristics under different operating conditions were analysed. The results showed that as the nozzle inclination angle increased, the entrainment coefficient (Ce) and the temperature ratio at the inlet and outlet (Rt) initially improved but then worsened. Simultaneously, the pressure loss coefficient (Cpl) increased with the inclination angle. The CRITIC weight method was employed to objectively allocate weights to Rt, Ce, and Cpl, determining the optimal solution. The results indicated that Rt and Cpl had significant and similar weights. The optimal solution was found in Case 10 (α = 5°, x = 4), with corresponding evaluation indices of Ce=2.38, Cpl=11.45, and =0.68. This study's findings are of great importance for enhancing the performance of marine gas turbines and reducing external infrared radiation.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42531356","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}

引用次数: 0

A novel approach for planning of shipbuilding processes 造船工艺规划的新方法

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-09-01 DOI: 10.21278/brod74402

Aytek Gungor, Y. Unsan, B. Barlas

引用次数: 0

Research on classification and navigational risk factors of intelligent ship 智能船舶入级及航行风险因素研究

4区工程技术

Brodogradnja Pub Date : 2023-09-01 DOI: 10.21278/brod74406

Wenjun Zhang, Yingjun Zhang

引用次数: 0

Principal component analysis of containership traffic in the Black Sea 黑海集装箱船运输的主成分分析

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-09-01 DOI: 10.21278/brod74404

Y. Garbatov, P. Georgiev

{"title":"Principal component analysis of containership traffic in the Black Sea","authors":"Y. Garbatov, P. Georgiev","doi":"10.21278/brod74404","DOIUrl":"https://doi.org/10.21278/brod74404","url":null,"abstract":"A novel quantitative analysis employing the Principal Component Analysis (PCA) of containership traffic in the Black Sea from 2018 to 2021 is performed. The study uses a matrix covering five ship size classes from A to E for four years of operation, from 2018 to 2021, accounting for ship traffic, CO2, fuel consumption (FC), shipping intensity, and eco and traffic efficiency. Only the first two principal factors are analysed because of their total variation weight. Shipping intensity, FC intensity, and CO2 intensity plays a significant role in the first factor, while Eco efficiency, FC efficiency, and Traffic efficiency are considered for the second factor. Notably, the set of parameters pertains to time and is strongly associated with DWT. Two principal components were identified, F1 and F2, where F1 integrates efficiency and intensity. At the same time, F2 separates the intensity from the efficiency conditional on the ship size and the year of operations. In the principal component F1 the activities of ships A and C differ from B, D and E, separating more efficiently from less efficiently used ships, and in F2, the activities of class sizes of ships C and D and E contrast A and B ships, distinguishing the big-size class ships from small ones. It was concluded that the most intensively used ships are the ship size classes C and D, and the most efficient are ship size classes A and B. The most intensive use of the ships was in 2020, followed by 2021, and the most efficient were in 2018, 2019. Based on the ship activities and using the Within-class variance, ships are grouped into two clusters of similar activities, where the first one, with lower variance and more homogeneous, includes only the ship size class A. The second one with a relatively large variance consists of the rest size of the ships. Linear relationships considering the intensity and efficiency are derived as a function of the main variables, where the factor loading represents the variable’s coefficient, given as a relative weight to any factor.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48615509","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}

引用次数: 0

The effect of PID control scheme on the course-keeping of ship in oblique stern waves 斜尾波中PID控制方案对船舶航向保持的影响

4区工程技术

Brodogradnja Pub Date : 2023-09-01 DOI: 10.21278/brod74408

Yunbo Li

引用次数: 0

Investigation of the optimum longitudinal single transverse step location for a high-speed craft 高速飞行器纵向单横台阶最佳位置的研究

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-06-01 DOI: 10.21278/brod74303

A. Avci, B. Barlas

引用次数: 0

Numerical study of trimaran wave load based on time-domain Rankine method 基于时域朗肯方法的三体船波浪载荷数值研究

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-06-01 DOI: 10.21278/brod74306

Haoyun Tang, Q. Wan, H. Ren

引用次数: 1

Robust optimal control of a nonlinear surface vessel model with parametric uncertainties 具有参数不确定性的非线性水面船舶模型的鲁棒最优控制

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-06-01 DOI: 10.21278/brod74307

Ahmad Irham Jambak, I. Bayezit

引用次数: 2

A comparison of regression models for the ice loads measured during the ice tank test 冰槽试验中冰荷载回归模型的比较

IF 1.8 4区工程技术

Brodogradnja Pub Date : 2023-06-01 DOI: 10.21278/brod74301

Seung Jae Lee, K. Jung, Namkug Ku, Jaeyong Lee

{"title":"A comparison of regression models for the ice loads measured during the ice tank test","authors":"Seung Jae Lee, K. Jung, Namkug Ku, Jaeyong Lee","doi":"10.21278/brod74301","DOIUrl":"https://doi.org/10.21278/brod74301","url":null,"abstract":"To evaluate the time-domain positioning performance of arctic marine structures, it is necessary to generate an ice load appropriate for the current position and heading of the structure. The position and orientation angle of a floating body continuously change with time. Therefore, an ice load is required for any attitude in the time-domain simulation. In this study, we present a fundamental technique for analyzing ice loads in the frequency domain based on data measured at various angles in the ice-water tank experiment. We perform spectral analysis instead of general FFT to analyze the ice load, which has the characteristics of a random signal. To generate the necessary ice load in the time domain, we must first interpolate the measured data in the frequency domain. Using the Blackman-Tukey method, we estimate the spectrum for the measured data, then process the data to generate the training set required for machine learning. Based on the results, we perform regression analysis by applying four representative techniques, including linear regression, random forest, or neural network, and compare the results with MSE. The deep neural network method performed best, but we provide further discussion for each model.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43985219","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}

引用次数: 0