利用准稳态、循环平均值等建模方法,给出了包含大型低速二冲程柴油机、轴系、螺旋桨和船体动力学的实时仿真模型。在螺旋桨特性计算中,提出了推力系数和转矩系数计算的简便算法,算法既能避免利用螺旋桨图谱的复杂计算过程,又能满足全工况范围的仿真需要。仿真程序是利用VC++开发实现的。仿真结果表明,动力装置在稳态和变工况下的计算结果与实船试航数据能够较好的吻合。螺旋桨特性计算的简便算法可以应用于螺旋桨特性的分析和建模,仿真模型可用于动力装置的性能分析、预测和调速器系统的设计和优化。
Based on the quasi steady method and cycle mean value method, a real-time mathematical model for propulsion system transient response of engine, shaft, propeller and ship hull dynamics is proposed. To calculate propeller's characteristics, the simplified regression functions for calculating thrust coefficient and torque coefficient are also given. This calculation method not only avoids the complicated calculation process of using characteristic maps but also meets the requirements of simulation over whole load range. The simulation code was programmed by Visual C + +. The simulation results showed that the steady and unsteady results matched well with the trial voyage results. The calculation method of propeller's characteristics can be used in analyzing and modeling propeller's characteristics, in engine performanee analyzing and prediction as well as in designing and optimization of governor system of marine diesel engine.