Influence Analysis Of Hull-propeller-rudder Interaction On Shafting State

As an important part of the Marine power system,the safety and reliability of Marine propulsion shafting are very important.Under the influence of different navigation conditions,the state of ship propulsion shafting is not invariable but always changing.If the sailing conditions change,the propeller at the stern will be affected by different wake fields,and then affect the propulsion shafting connected with it.It is very easy to distort the shafting state under bad working conditions,and even cause serious accidents of shafting fracture,which threaten the safety of ships.Therefore,it is necessary to deeply study the changing trend of shafting state under different navigation conditions,to have a preliminary expectation of the change of shafting state,and to better reduce the probability of the occurrence of danger.In this paper,the research status of propeller hydrodynamic force,hull–propeller-rudder interaction,and shafting state at home and abroad are analyzed.The numerical simulation of the model was carried out by using computational fluid dynamics software,and the effectiveness of the numerical simulation method was verified.Based on the calculation of the shrinkage model,the numerical simulation of the hull–propeller-rudder integration model in real scale was built and carried out.On the premise of verifying the reliability of the numerical simulation results,the numerical calculation of different working conditions was carried out,and the hydrodynamic force of the propeller was monitored.The representation parameters of shafting state were proposed,and the influence of shafting state change was studied by combining the simulation results on a real scale.The main research contents of this paper are as follows:(1)The numerical simulation of the scaled hull-propeller model.Firstly,the K-εturbulence model and SIMPLE algorithm were used to solve the RANS.The multiple reference frame(MRF)method was used to simulate the propeller rotation,and the open-water performance of the KP505 propeller was numerically calculated.Then,the multiphase flow is simulated by the VOF method,and the towing numerical simulation of the KCS naked ship(without propeller rudder)is carried out.Based on propeller open water calculation and naked towing calculation,a self-propelled numerical simulation of the hull-propeller model is carried out to verify the feasibility of self-propelled numerical simulation.(2)Numerical simulation of the full-scale hull-propeller-rudder integration model.A full-scale hull-propeller-rudder calculation model with KCS hull,KP505 propeller,and M1203 rudder as the main body was established.Based on the numerical simulation of the scaled hull-propeller-rudder model,the numerical simulation of full-scale hull-propeller-rudder self-navigation was carried out.Then,according to the different working conditions,the numerical simulation under different rudder Angle and drift Angle is carried out to explore the variation trend of propeller hydrodynamic force with rudder Angle and drift Angle.(3)Influence of propeller hydrodynamic change on the shafting state under hull-propeller-rudder interaction.A hybrid finite element calculation model was established by combining solid propeller and beam model propulsion shafting,and the correctness of the finite element calculation method was verified based on traditional calculation results.Based on the hybrid model,the influence of shafting state under different working conditions was studied,and the influence of shafting state change on vibration transmission characteristics was analyzed.