Simulation studies around the steering system of the azimuthing propulsor

Abstract

In this study, the steering load, the steering control and the gear failure of the steering system of the azimuthing propulsor are simulated and investigated respectively. In this research, CFD simulation was used to obtain the steering load moment for a azimuthing propulsor with different advance coefficients in the azimuthing range of 0∘ to 180∘. Then the simulation results were compared to the open water experiment results to analyze the reasons for the similarities and differences. Finally, the reason for the fluctuations and the fluctuations frequency calculation method were discussed. A co-simulation model of the gear transmission system and the hydraulic control system was built to simulate the steering control process. Due to the limited braking speed in small angle position feedback control, a speed feedback position control method was proposed. Taking into account the influence of fluctuating variable load on the hydraulic system pressure and the dynamic gear meshing force, the optimal control parameters were found, and the final control effect was significantly improved. In view of the pressure change of the hydraulic system contains a wealth of information on gear torsional vibration, the influence of gear failure on the hydraulic system pressure was discussed considering the two gear failure modes of broken teeth and uniform wear. The input load is divided into constant load and fluctuating load, and the test results was consistent which provides a basis for diagnosing azimuth gear faults.