Chinese Journal of Ship Research is supervised by China Shipbuilding Industry Corporation (CSIC) and sponsored by China Ship Development and Design Center (CSDDC). The journal is a notable academic journal in the field of naval architecture, shipbuilding and marine engineering in China. It aims to push forward theoretical innovation and advanced technologies. Its scope covers the latest technological breakthroughs, trends, concepts, and discoveries related to the marine industry, naval architects and marine engineering.
The journal is included in CSCD.
Honorary Chairmen AI Ting-yuan, SHAO Kaiwen, WANG Jianguo
Chairman WU Xiaoguang
Vice Chairmen CAI Daming, LIN Zhongqin, MIAO Yu, SHAO Xinyu, WANG Zili, XIA Guihua, XU Qing, ZHANG Qingjie
Invited members DING Rongjun(member of CAE), GONG Xianyi(member of CAE), LU Jianxun(member of CAE), MA Yuanliang(member of CAE), PAN Jingfu(member of CAE), QIU Zhiming(member of CAE), SUN Cong(member of CAE), SUN Yufa(member of CAE), TAN Jianrong(member of CAE), WANG Shunting(member of CAE), WEN Xueyou(member of CAE), YANG Desen(member of CAE), YANG Shie(member of CAE), ZHANG Jinlin(member of CAE),ZHU Yingfu(member of CAE)
[Objectives] With the continuous improvement of submarines’ stealth property and combat capabilities, the underwater challenges faced by surface ships are increasingly becoming serious. To enhance the capabilities of overall scenario awareness, sustained surveillance, and early warning of submarines, this paper systematically studies the long-range target detection method using underwater explosive sound sources as the emission source. [Methods] According to the principle of bistatic sonar localization, the solution equation of underwater targets is given. According to the energy relationship, the mathematical model of the maximum detectable range of the system is deduced. The spatial distribution of the target localization error is analyzed by numerical simulation, and the target detection range and localization accuracy of explosive sound sources with different deploying distances are examined. [Results] The results show that the detection of underwater targets based on explosive sound sources cannot expand the detection range in the whole plane, but it can obtain greater detection advantages in a certain angle range near the baseline extension. On this basis, by reasonably allocating multiple explosive sound sources, we can increase the warning distance of the submarine. [Conclusions] Effective target information can be provided for aircraft-based on-called antisubmarine operations.
ObjectivesThe navigation attitudes (sinkage and trim) of a semi-planing ship (at Froude number Fr> 0.4) have significant effects on its resistance performance during the voyage. The sinkage and trim effects on the resistance components (frictional resistance and pressure resistance) are discussed.MethodsA CFD study is carried out on the resistance performance of a trimaran in calm water, and the k-ε turbulent model and overlapping grids are adopted. The free model and constrained model are computed. The computed results are compared to analyze the effects of sinkage and trim on the resistance components. ResultsThe results show that the change in total resistance caused by sinkage and trim is more than 20% in semi-planing conditions. The sinkage and trim have a significant effect on the pressure resistance, up to nearly 50%, and a relatively small effect on frictional resistance, less than 8.5%. More than 90% of the resistance increase caused by motion attitude comes from the change in pressure resistance.ConclusionsPredicting the motion attitudes and resulting pressure resistance changes accurately is extremely important for a semi-planing trimaran.
[Objectives] Aiming at the distributed hybrid energy storage system (HESS) in the vessel integrated power system (IPS), a multi-HESS coordinated control method based on the state of charge (SOC) of the energy storage device (ESD) was proposed to achieve the relative consistency among multi-HESS and the reasonable power allocation between supercapacitor and battery within a single HESS. [Methods] The droop control method will be adopted in the outer control loop of a single HESS to realize the initial power allocation, while the master-slave control mode will be adopted in the inner control loop to reduce the communication demand among multi-HESS. Given the characteristics of a fast dynamic response but the small capacity of supercapacitor and large capacity of battery, the SOC value of the supercapacitor is calculated to obtain the output power of the battery within a single HESS. Between multi-HESS, the total charging/discharging power of each HESS is calculated based on the SOC value of the internal battery. [Results] Through the simulation of PSCAD/EMTDC, the discharging response characteristics of multi-HESS under high energy load switching and random fluctuation conditions are verified. Under the charging-discharging mode transformation condition, the bus voltage fluctuation is within the allowable range of 2.5%. The SOC of a supercapacitor is controlled between the upper and lower limits, and the SOC consistency of two supercapacitor units is maintained. In both charging and discharging modes, lithium batteries operate only when the supercapacitor is limited. [Conclusions] On the premise of not depending on the high-low pass filter unit, the multi-HESS coordinated control method has better bus voltage stability and strong robustness.
Objectives In order to improve the quality of sinusoidal waveform output by the ship's high-frequency inverter charging device and reduce the CPU occupancy rate, this paper proposes a sinusoidal pulse width modulation (SPWM) method of asymmetric regular sampling based on tangent approximation. Methods According to the basic principle and calculation method of the asymmetric regular sampling SPWM method based on tangent approximation, a Matlab/Simulink simulation model is built, and then the software algorithm flow that can be used in the high-frequency inverter charging device is designed together with the actual output of the tangent approximation method. The effects are then compared and verified by experiments. Results The simulation results show that under pure resistive load and resistive inductive load, the total harmonic distortion (THD) of the load-end waveform based on the tangent approximation method is 2.12% and 2.08%, respectively, and its waveform quality is better than that of symmetric regular sampling. The experimental results show that the THD of a load-end waveform based on the tangent approximation method is significantly lower than that of the symmetric regular sampling method. When the effective value of the input line voltage is 580 V (the modulation ratio is 0.8), the quality of the output waveform is relatively optimal. Conclusions The asymmetric regular sampling SPWM method based on tangent approximation overcomes the shortcomings of the traditional symmetric regular sampling method, such as the low quality of the output waveform and high sampling frequency and high CPU occupancy rate in the traditional asymmetric regular sampling method. The research results can provide a reference for the design of high-frequency inverter charging devices on ships.
Objectives The bandwidth of a wireless IP network in a warship formation is limited and time-varying. In order to meet the time requirements for cross-platform task operation in the formation of combat applications, we should study the cross-platform task scheduling algorithm under the network bandwidth constraints. Methods In this paper, a task scheduling model based on the wireless IP network in a warship formation is proposed. A communication mode entailing a “task initiator” and “task responser” is adopted to realize the task scheduling of “earliest deadline first (EDF) + first come first serve”. The extended EDF algorithm is proposed. On the basis of the traditional single-platform single-processor real-time scheduling algorithm, the calculation of task execution time is transformed from processor time to network time, which can be applied to ship formation, deducing the judging condition of task scheduling ability. Then, the proposed method is verified by tests. Results The results show that the scheduling capability of a cross-platform task set for warship formation can be calculated through the construction of a test network environment. Conclusions The theoretical model and algorithm proposed in this paper are applicable and important for guiding the task planning and scheduling of wireless IP networks in warship formations.
[Objectives] For an electrical propulsion system, the transient torque induced by short-circuit faults is so large that it will exert a great impact on the safety of the shipboard electrical propulsion system. In order to evaluate the problem, we propose a simulation method for analyzing the torsional vibration of a propulsion system under a short-circuit-induced torque impulse in the time domain. [Methods] On the basis of the torsional vibration analysis theory, a time-domain model is developed, and the system response to a transient torque impulse induced by a short-circuit fault is expressed. Then by using the proposed simulation model, we calculate and analyze the natural frequencies and response to the transient torque impulse for an electrical propulsion system. [Results] The simulation results show that the dynamic characteristics of the system have a prominent role in the transmission of torque impulse, and components at frequencies above the first resonance frequency see a substantial reduction, so the torque response of the propeller is mainly based on the first resonance frequency component. If an elastic coupling is inserted into the propulsion motor and the shafting, the torque response of the system can be significantly decreased. The peak value increases with motor speed, and vibratory torque can reach several times the value of the mean torque, causing the gears to rattle and the torsion vibratory stress to grow as a result. [Conclusions] The proposed simulation modeling method is suitable for analyzing the torsional vibration response of an electrical propulsion system subject to a short-circuit-induced impulse load, and numerical calculations should be carried out to check the reliability of the system during the design process.
Objectives To identify and quantify uncertain factors in the modeling and simulation of ships suffering a non-contact underwater explosion, we study the influence of high-dimensional random variables on the output of the system. Methods Following statistical characteristics and engineering knowledge, the lognormal distribution is used to describe uncertain physical quantity, and the Beta distribution is utilized to depict uncertain empirical parameters. Rosenblatt transformation is explored to transform these correlated random variables into Gaussian variables satisfying independent identical distribution. There are a variety of uncertain factors due to the complexity of the model. The computational efficiency is greatly improved when homogeneous Wiener chaos with quadratic adaptive basis function is used to tackle improbability propagation of these input uncertainties. Concerns over a spring device in the deck, expectation, standard deviation, confidence interval, and the probability density function of the quantity of impulsive are presented via the proposed method. Results Oscillation of the ship always exists after the arrival of a shock wave. The oscillation of the standard deviation is much more forceful than the mean value. Conclusions The results can be used to predict the impact of a detonation and provide guidance for the reinforcement ability of the ship.
Objectives The resonance changer (RC) is designed under rigid boundary conditions and then applied to the elastic coupling boundary condition. This paper explores the influence of changes in boundary conditions on RC parameter design and its vibration reduction effect. Methods Considering the characteristics of the shafting rotor, a dynamic model of a shafting-hull coupling system with an RC is established. On the basis of the transfer matrix method, the vibration and force transfer characteristics of the system are analyzed. The structural parameters of the RC are designed according to the shafting longitudinal vibration characteristics under rigid boundary conditions and then applied to the hull. Results The results show the feasibility of the above parameter design and application scheme. The influence of the anti-resonance vibration isolation mechanism on the system can be divided into the stiffness region, anti-resonance region, and mass region. Through sensitivity analysis, it is proposed that the structural parameters of the RC are adjustable. Conclusions The results of this study can provide valuable references for the application of RC to full-sized ships.
Objectives With the sustained demand for improving operational efficiency and safety of the offshore platforms with moonpools, the resonance problems become more critical due to the motion of platforms in waves and fluid flow in the moonpools. Methods To effectively solve this problem based on the constant boundary element method of potential flow theory, this paper developed a numerical simulation program to calculate the interaction between wave currents and three-dimensional objects. By selecting a drillship, we carried out frequency-domain numerical calculations for its motion and compared the calculation results of those of AQWA, which verified the reliability of the program. Then, we compared the calculation results of wave and current conditions with those of the experiment, which verified the accuracy of the numerical method. Results By comparing the resonance phenomena of ships containing the moonpools in the heave and sway motion under varying length-width ratio conditions and different drafts of the moonpool, different wave incidence angles, and with or without sailing speed, the introduction of velocity in the upstream situation will modulate and intensify the common vibration of the moonpool. Conclusions The research can provide a reference for predicting the ship’s motion response with the moonpool and reduce the risk of resonance.
[Objectives] With the wide application of energy management system (EMS) networks in shipboard power systems, their non-ideal characteristics have a growing effect on the system performance. To analyze the close-coupling feature of the two systems, we propose a cyber-physical co-simulation method that combines information network and power system simulation. [Methods] This method takes OPNET and Matlab/Simulink as an information network and power system simulator respectively and proposes the software data exchange interfaces and co-simulation synchronization method based on a uniform co-simulation framework. A co-simulation model of two synchronous generators running in parallel with loads is built, and the effect of EMS information network characteristics including link latency and background traffic on secondary power distribution is studied. [Results] Simulation results indicate that after link latency (2 and 5 ms) is added, the total latency of the control process is around 12 and 30 ms. The fixed latency on network links significantly affects the response of the power system. When network links are overloaded by background traffic, the packet latency and closed-loop control latency of system will increase, and the system will diverge after a certain period. [Conclusions] The proposed method provides an effective simulative method for future research on shipboard close-coupled EMS information network and power system.
