Research On Dynamic Characteristics Of Propulsion Shafting Based On Simulink

Due to the many components and complex layout of ship propulsion shafting,and different ship applications,the cost of safety assessment of the working state of propulsion shafting is high,and some special navigation conditions are also difficult to achieve.With the rapid development of computer technology,some software can be used to establish corresponding propulsion shafting simulation models according to different research purposes and requirements,and can also simulate different navigation conditions and simulate the dynamic response of the propulsion shafting.and analysis.The research contents of this paper include:(1)According to the composition characteristics of the propulsion shafting,the mathematical model of each component of the propulsion shafting is studied.The modeling method of propulsion shafting is divided into two parts: diesel engine and shafting components.Among them,the diesel engine adopts the quasi-steady-state modeling method,and each component of the shafting adopts the modeling method of lumped parameters.At the same time,the structural characteristics of the propulsion shafting of 208 K bulk carrier are analyzed.First,the propulsion shafting is simplified by the lumped parameter method,and the lumped parameter model of the propulsion shafting is established,and the free vibration calculation method of the propulsion shafting is used.,the free vibration calculation of its propulsion shafting model is carried out,and finally the natural frequency results of the propulsion shafting of the ship are obtained.(2)The calculation method of the excitation,damping and frequency domain steady-state response of the propulsion shafting is studied,and the steady-state calculation of the propulsion shafting of the 208 K bulk carrier is carried out,and the calculation result of the steady-state response of the propulsion shafting of the ship is obtained.According to the excitation influence of the propulsion shaft system,the working process of the diesel engine,the modeling method and the dynamic simulation method of each working process are studied.The simulation method of the dynamic response of the propulsion shafting is studied,and the calculation method of the dynamic response of the propulsion shafting in the time domain is established by combining the Newmark-β integral method and the steady-state response calculation method,and the calculation method of the dynamic change of the rotational speed of the propulsion shafting under load is studied.(3)Based on the Matlab/Simulink simulation platform and the method of establishing the dynamic model of the diesel engine,combined with the excitation form of the propulsion shafting,the dynamic simulation model of the working process of the diesel engine is established,and the dynamic simulation model of the propulsion shafting is established by establishing the dynamic model of the propulsion shafting..According to the response characteristics and navigation conditions to be studied,a simulation model for dynamic response calculation of propulsion shafting is established.By combining all the models according to the structural characteristics of the propulsion shafting,a general dynamic response simulation model of the entire propulsion shafting can be established.(4)Taking the 208 K bulk carrier propulsion shafting as the research object,the dynamic torsional vibration response characteristics were analyzed.The Simulink dynamic model of the propulsion shafting was established,and the response results in the frequency domain and the test results were compared respectively to verify the correctness of the general dynamic model of the propulsion shafting.At the same time,the ice load excitation is applied to the dynamic model of the propulsion shafting,and the dynamic response of the propulsion shafting is studied and analyzed.The results show that the angle difference between the interaction angle between the ice load and the propeller and the angle at which the first cylinder of the diesel engine reaches the top dead center will affect the torsional vibration response of the propulsion shafting,and the torque of the propulsion shafting reaches the maximum value at a certain phase angle.