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991.
The effect of line voltage drop is considered larger on loads, especially on asynchronous motor, transformers and other non-linear
load parameters in power system of large ships. A novel power flow method based on improved node voltage method is proposed,
and a typical ship power system, which has 2 power stations and 10 nodes, with closed-loop design but open-loop operation,
is taken as an example. Simulation results show that the improved power flow calculation method has achieved higher accuracy
and better convergence. 相似文献
992.
Problems experienced during Floating Production, Storage and Offloading (FPSO) tandem offloading operations were investigated.
The aim of this research was to improve the reliability of such systems, and it needed a means to assess them. Time-domain
simulation and analysis of offloading systems was performed using the multi-body mooring software ARIANE 7.0. Hydrodynamic
interaction between the vessels was considered. The responses of the offloading system in different loading cases, different
parameters of offloading hawsers and the effects of challenging environmental conditions were calculated. There was a focus
on the problems of relative motion between the two bodies and its effects on the intensity of hawser forces. Minimum relative
distance, maximum relative headings and maximum tension in the hawsers of offloading systems were obtained by time-domain
analysis. The time-domain analysis was effective and comparative study can be used to optimize parameters of the system and
extend operating limits. 相似文献
993.
海上风力机安装技术研究(英文) 总被引:1,自引:0,他引:1
Wind power has made rapid progress and should gain significance as an energy resource, given growing interest in renewable
energy and clean energy. Offshore wind energy resources have attracted significant attention, as, compared with land-based
wind energy resources, offshore wind energy resources are more promising candidates for development. Sea winds are generally
stronger and more reliable and with improvements in technology, the sea has become a hot spot for new designs and installation
methods for wind turbines. In the present paper, based on experience building offshore wind farms, recommended foundation
styles have been examined. Furthermore, wave effects have been investigated. The split installation and overall installation
have been illustrated. Methods appropriate when installing a small number of turbines as well as those useful when installing
large numbers of turbines were analyzed. This investigation of installation methods for wind turbines should provide practical
technical guidance for their installation. 相似文献
994.
CHENMing-jie LIDian-pu ZHANGAi-jun 《船舶与海洋工程学报》2004,3(1):64-70
Chaotic synchronization is a branch of chaotic control. Nowadays, the research and application of chaotic synchronization have become a hot topic and one of the development directions is for the research on chaos. In this paper, a universal nonlinear stateobserver is presented for a class of universal chaotic systems to realize the chaotic synchronization, according to the theory of state-observer in the modem control theory. And theoretic analysis and simulation results have illustrated the validity of the approach. Moreover, the approach of synchronization proposed in this paper is very easy, flexible and universal with high synchronization precision. When the approach is applied to secure communication, the results are satisfying. 相似文献
995.
SUICheng-cheng YANGYong-tian JIARong-zhen 《船舶与海洋工程学报》2004,3(1):52-56
Real-time modeling and simulation of flight system are the key parts of simulator. After describing the architecture of simulator for a newer fighter, author presents the composition of flight system and its mathematic models. In this paper, aircraft is regarded as an elastic flight body. And a new integrated algorithm which can remedy the shortcoming of Euler method and four-element method is used to calculate the Eulerian angles of aircraft. Finally, the software implementation of the flight system is given in the paper. 相似文献
996.
ZHANGMing-jun HANZhi-xue 《船舶与海洋工程学报》2004,3(1):46-51
In this paper we present two strategies of AUV (Autonomous Underwater Vehicle) region detection and an approach to decompose the detection region according to the direction of the ocean current. In the task of local detection and identification, the algorithm against the ocean current was proposed. In the tasks of closing obstacle, going back or moving, the fuzzy logic theory was used to solve the effect of ocean current. In one of our strategies the concept of weighted journey based on the angle between heading and ocean current is suggested and the TSP‘s exact optimal result is utilized to solve the global path planning. Simulations demonstrate the feasibility of this approach. 相似文献
997.
WUFu-bing ZENGNian-dong ZHANGLiang WUDe-ming 《船舶与海洋工程学报》2004,3(1):1-6
Continuous vortieity panels were used to model general unsteady inviscid, incompressible, two-dimensional flows. The geometry of the airfoil was approximated by series of short straight segments having endpoints that lie on the actual surface. A piecewise linear, continuous distribution of vorticity over the airfoil surface was used to generate disturbance flow. The no-penetration condition was imposed at the midpoint of each segment and at discrete times. The wake was simulated by a system of point vortices, which moved at local fluid velocity. At each time step, a new wake panel with uniform vortieity distribution was attached to the trailing edge, and the condition of constant circulation around the airfoil and wake was imposed. A new expression for Kutta condition was developed to study the interference effect between two impulsively started NACA0012 airfoils. The tandem arrangement was found to he the most effective to enhance the lift of the rear airfoil. The interference effect between tidal turbine blades was shown clearly. 相似文献
998.
LINDe-ming JINHong-zhang LIQi WUHong-mei 《船舶与海洋工程学报》2004,3(2):69-72
Now the research on the complex system is a hot spot. Brittleness is one of the basic characteristics of a complex system. In a complex system, after one of subsystems is struck to be collapsed, the whole system will collapse. Meanwhile, cellular automata is a discrete dynamic system. When the rule is given, the cellular automata could be defined. Then it can imitate the complex action. Cellular automata is used to simulate the brittleness action in this study. Entropy was used to analyze the action and get the rule. Then,three normal brittleness models were given. The result shows that the brittleness of complex system is existent and in addition some important behavior mode of complex system brittleness has been achieved. 相似文献
999.
HAOYan-ling SHENDong-hui QIANHua-ming DENGMing-hui 《船舶与海洋工程学报》2004,3(2):50-57
This paper aims at finding a solution to the problem aroused in complex system simulation, where a specific functional federation is coupled with other simulation systems. In other words, the communication information within the system may be received by other federates that participated in this united simulation. For the purpose of ensuring simulation system unitary character, a hierarchical federation architecture (HFA) is taken. Also considering the real situation, where federates in a complicated simulation system can be made simpler to an extent, a multi-resolution modeling (MRM) method is imported to implement the design of hierarchical federation. By utilizing the multiple resolution entity ( MRE ) modeling approach, MRE for federates are designed out. When different level training simulation is required, the appropriate MRE at corresponding layers can be called. The design method realizes the reuse feature of the simulation system and reduces simulation complexity and improves the validity of system Simulation Cost (SC). Taking submarine voyage training simulator (SVTS) for instance, a HFA for submarine is constructed in‘this paper, which approves the feasibility of studied approach. 相似文献
1000.
The objective of this paper is to study the nonlinear coupling internal resonance of the heave, roll, and pitch response performance of a spar platform when their frequencies are in the ratio of 2:1:1 under wave and vortex exciting loads. The three degree-of-freedom (DOF) nonlinear coupled equations are established by considering a time-varying wet surface with a first-order wave force in heave and pitch and a vortex-induced force in roll. The first-order steady-state response is solved using the multi-scale method in heave main resonance. The multiple solutions of the motion equations are discussed using the analytic method and a numerical simulation. A sensitivity analysis is conducted to test the influence of the damping and internal detuning parameter. The regions of multiple solutions are found, and the jump phenomenon exists with the changes of the wave excitation. The regions of multiple solutions depend on the values of damping and detuning parameter. 相似文献