Research On The Effect Of External Circulation Diversion On The Noise Of The Propeller In The Reverberation Tank

Propeller noise is one of the main components of ship noise.The measurement of propeller acoustic characteristics is generally carried out in open waters such as lakes and oceans.However,considering the measurement efficiency and time,the propeller noise is generally measured in the reverberation pool during the design stage of propellers with propellers.Therefore,it is particularly important to study the influence of limited space on propeller noise.Inspired by the reverberation box method to measure the cavitation noise of the propeller in the water tunnel,the circulating reverberation tank is used to measure the noise of the propeller with propeller.The hydrodynamic performance of the propeller with propeller in the reverberation tank and the influence of the propeller,and the practical value and engineering significance of this kind of circulating reverberation tank are explored.In this paper,the influence of the circulating diversion system on the noise of the propeller with propeller in the reverberation tank is studied by the method of combining simulation and experiment.In the simulation part of the thesis,the numerical simulation of the hydrodynamic performance of the propeller in three working environments of free space,closed space and limited space with open diversion is carried out,and the pressure distribution characteristics and propeller wake field characteristics of propeller blades under different working environments are compared.Numerical simulation of propeller radiated noise.The noise of the propeller is measured in the anechoic tank and the circulating water tank.The noise measurement of the propeller with propeller is carried out when the reverberation tank is opened with the circulating diversion,and the noise measurement of the propeller with propeller is carried out when the diversion is closed and in the anechoic tank.Compared with the measurement results of the propeller noise,the influence of the external circulation diversion device on the noise of the propeller with propeller in the reverberation tank is studied.The simulation and experimental results show that compared with the propeller wake field in free space,the enclosed space will have a significant impact on the propeller wake field,making the wake field more turbulent,the limited space of opening the diversion can play a certain role in improving the propeller wake field.The limited space will increase the working noise of the propeller with propeller,and opening the diversion in the limited space can improve the noise of the propeller with propeller,so that the noise of the propeller with propeller is close to the noise of the propeller in free space.