Journal of the Japan Society of Naval Architects and Ocean Engineers最新文献_第10页

Study on implications for design of fuel transition in decarbonization of ship 船舶脱碳对燃料转换设计的启示研究

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.37.107

Koichi Sato, Daiki Tsuchida, Katsuyuki Suzuki

引用次数: 0

Simulation of Ship Drift Motion with a Simplified Mathematical Model under the Wind 用简化数学模型模拟风作用下船舶漂移运动

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.31.47

Y. Yoshimura, K. Takase, Hirofumi Fukui, Hideyuki Suzuki, S. Hirabayashi

{"title":"Simulation of Ship Drift Motion with a Simplified Mathematical Model under the Wind","authors":"Y. Yoshimura, K. Takase, Hirofumi Fukui, Hideyuki Suzuki, S. Hirabayashi","doi":"10.2534/jjasnaoe.31.47","DOIUrl":"https://doi.org/10.2534/jjasnaoe.31.47","url":null,"abstract":"Dead ships in rough sea make strong drifting motions and sometimes cause the significant accidents such as grounding or destroying offshore structures. For the prediction of such drift motion, it is necessary that the suitable mathematical model should be provided. Although many mathematical models for the conventional maneuvering ship motion are proposed and widely used, most of them are limited within the conventional maneuvering motion. They cannot be used for the large drift angle such as 90° including the zero-ship speed turning. It is very difficult for the conventional mathematical model to express the hull forces in such drift motion. One of the authors tried to make them using crossflow drag model1), 2), 4), 5), 6). However, the above models include the longitudinal integral terms, which makes the difficulties when using for real-time simulators or system identifications. In this paper, the authors have developed a simple mathematical model that has the almost equivalent hydrodynamic force characteristics for conventional crossflow model instead of using the integral terms. The new model can also express the hydrodynamic forces with large drift and turning motion including zero ship speed condition. In order to validate the mathematical model, the drift tests in the uniform wind were carried out and the simulated results were compared with the measured data. From the comparison between experimental results and simulated them, it is found that the proposed mathematical model as well as the original crossflow drag model make it possible to predict the wide range of drift motion. Furthermore, the parameters in the proposed mathematical model can be easily obtained from the principal particulars of ship based on the regression analysis. Then the drifting simulations become very easy by using the proposed simple mathematical model and the empirical formulas of the parameters.","PeriodicalId":192323,"journal":{"name":"Journal of the Japan Society of Naval Architects and Ocean Engineers","volume":"60 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127578628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Safety Evaluation of LNG Bunkering in Ship-to-Ship Configuration Using a Flexible Metal Hose LNG船对船加注使用柔性金属软管的安全性评价

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.31.107

K. Yukawa, M. Saito, Hiroki Manabe, D. Iwakura

引用次数: 0

A Strip Method Including nx-Related Terms and Its Effects on Propeller Inflow Velocity in Waves 包含nx相关项的条形法及其对波浪中螺旋桨入流速度的影响

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.29.39

Y. Kitagawa, M. Kashiwagi

引用次数: 5

Algorithm Based on Deep Reinforcement Learning for Irregular Shape Nesting Problem 基于深度强化学习的不规则形状嵌套算法

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.33.209

Tomoyuki Taniguchi, M. Hirakata, Junichi Man

{"title":"Algorithm Based on Deep Reinforcement Learning for Irregular Shape Nesting Problem","authors":"Tomoyuki Taniguchi, M. Hirakata, Junichi Man","doi":"10.2534/jjasnaoe.33.209","DOIUrl":"https://doi.org/10.2534/jjasnaoe.33.209","url":null,"abstract":"An automatic nesting algorithm based on deep reinforcement learning for shipbuilding is proposed. Automatic nesting method is desired because of the large number of parts to be placed. The nesting problem in shipbuilding is very difficult because of the relatively small area where they can be placed and the variety of shapes that can rotate freely. Since it is very difficult to manually create effective placement rules, this paper proposes an algorithm to generate rules autonomously based on reinforcement learning. To apply reinforcement learning to the nesting problem, we organized the problem as a Markov chain process. Based on deep q network, a type of reinforcement learning, we used the components of a real ship's block to learn the network parameters. The parts are represented in pixel format. It is confirmed that the present method was superior to the conventional method, and the results were comparable to those of a skilled person. However, for unlearned members, the results are inferior to those of the conventional method. This problem can be solved by relearning including unlearned components.","PeriodicalId":192323,"journal":{"name":"Journal of the Japan Society of Naval Architects and Ocean Engineers","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122495232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Power Production Efficiency Improvement of a Point Absorber Type Wave Energy Converter by Model Predictive Control 用模型预测控制提高点吸收型波浪能变换器的发电效率

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.29.171

Tomoki Taniguchi, T. Fujiwara, S. Inoue, T. Ohtsuka

{"title":"Power Production Efficiency Improvement of a Point Absorber Type Wave Energy Converter by Model Predictive Control","authors":"Tomoki Taniguchi, T. Fujiwara, S. Inoue, T. Ohtsuka","doi":"10.2534/jjasnaoe.29.171","DOIUrl":"https://doi.org/10.2534/jjasnaoe.29.171","url":null,"abstract":"This paper numerically investigates motion and power production characteristics of a point absorber type wave energy converter (WEC) using a model predictive control (MPC). The MPC is able to maximize power production while handling hard constraints, such as maximum motion, control force and so on. Motion and power production characteristics of the MPC were compared with two conventional control methods, the approximate complex-conjugate control with considering the copper loss (ACL) and the resistive loading control (RLC), under the sea condition of Japanese typical joint probability distribution based on a 21-year high-resolution hindcast dataset. From the numerical simulation, it was found that motion and power production characteristics of the MPC were comparable to these of the ACL if the wave height was low enough not to activate the MPC’s constraints. As the wave height increased, the two conventional control methods, excluding the MPC, couldn’t keep the WEC’s motion constraint. Moreover, the sea conditions in which the WEC with the MPC can operate as the power production mode was broadened compared with the two conventional control methods. Through the numerical simulations, it can be said that the WEC with the MPC is feasible in the sea","PeriodicalId":192323,"journal":{"name":"Journal of the Japan Society of Naval Architects and Ocean Engineers","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122664726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Study on Safety Assessment of Floating Horizontal Axis Tidal Turbine with Tank Test 浮动式水平轴潮汐能水轮机安全评价及试验研究

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.31.195

T. Chujo, K. Haneda, S. Ishida, R. Matsui, T. Nimura, S. Inoue

引用次数: 0

Underwater Cruise Simulation of an Autonomous Underwater Vehicle Using a Nonlinear Model Predictive Control 基于非线性模型预测控制的自主水下航行器水下巡航仿真

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.34.99

Kana Miyazawa, M. Arima, Tomoki Taniguchi, Jun Umeda, T. Fujiwara

引用次数: 0

Experimental Study on Parametrically Excited Oscillation of a Spar-Buoy Under Mathieu Instability Mathieu不稳定性下Spar-Buoy参数激振振荡的实验研究

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.30.97

Peng Xu, T. Iseki

{"title":"Experimental Study on Parametrically Excited Oscillation of a Spar-Buoy Under Mathieu Instability","authors":"Peng Xu, T. Iseki","doi":"10.2534/jjasnaoe.30.97","DOIUrl":"https://doi.org/10.2534/jjasnaoe.30.97","url":null,"abstract":"The occurrence of the Mathieu-type instability was investigated theoretically and experimentally. The main aim of this paper is utilization of auto-parametrically excited oscillation to increase efficiency of wave energy converters. In this paper, the subject is the auto-parametrically excited oscillation of a spar-buoy type point absorber with the coupled motions of pitch and heave. A spar-buoy model with innovative ballast control system was made and the model experiments were carried out to realize the large oscillating motion based on the Mathieu-type instability. The ballast control system installed in the buoy model can make the ballast move in the vertical direction to realize a certain change of the pitch natural period. Free-decay experiments were performed to determine the natural frequencies and damping ratios with different ballast positions. During the experiments in regular waves, it was observed that the pitch motion became unstable and the large pitch occurred suddenly. Based on time histories of experimental results, the points (peaks and troughs) are extracted near the large pitch occurring and t he periods of transient states were calculated to derive the parametrical values of stability. Considering these values with plotted stability chart of Mathieu equation, the occurrence of the large pitch motion is discussed.","PeriodicalId":192323,"journal":{"name":"Journal of the Japan Society of Naval Architects and Ocean Engineers","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129741394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Practical Correction Method for Added Resistance in Oblique Waves Considering the Influence of Roll Motion 考虑横摇影响的斜波附加阻力实用修正方法

Journal of the Japan Society of Naval Architects and Ocean Engineers Pub Date : 1900-01-01 DOI: 10.2534/jjasnaoe.34.1

Saori Yokota, M. Tsujimoto, A. Sakurada, M. Kuroda

引用次数: 0